Fix case-insensitive anchor ID collision in markdown help output (#10095)

Fixes #10083

The markdown help output (`slangc -help-style markdown -h`) generates
explicit `<a id>` anchor IDs for headings using case-sensitive
deduplication, but GitHub's markdown renderer generates heading IDs
case-insensitively. This causes the `## Target` category heading and `##
target` value section heading to produce non-colliding explicit anchors
(`Target` and `target`), while GitHub assigns them colliding auto-IDs
(`target` and `target-1`). The auto-ID `target-1` for `## target` then
coincides with the explicit anchor for the `### -target` option, so
clicking "target" in GitHub's right-side navigation scrolls to the
`-target` option instead of the target value list.

This fix lowercases anchor ID prefixes in `_getLinkName` so that
deduplication matches GitHub's case-insensitive behavior. The explicit
anchors now align with GitHub's auto-generated heading IDs, and the
right-side navigation links to the correct sections.

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: aidanfnv

docs/command-line-slangc-reference.md

@@ -12,14 +12,14 @@ slangc -help-style markdown -h
 ```
 ### Quick Links
 
-* [General](#General)
-* [Target](#Target)
-* [Downstream](#Downstream)
-* [Debugging](#Debugging)
-* [Repro](#Repro)
-* [Experimental](#Experimental)
-* [Internal](#Internal)
-* [Deprecated](#Deprecated)
+* [General](#general)
+* [Target](#target)
+* [Downstream](#downstream)
+* [Debugging](#debugging)
+* [Repro](#repro)
+* [Experimental](#experimental)
+* [Internal](#internal)
+* [Deprecated](#deprecated)
 * [compiler](#compiler)
 * [language](#language)
 * [language-version](#language-version)
@@ -33,19 +33,19 @@ slangc -help-style markdown -h
 * [debug-level](#debug-level)
 * [file-system-type](#file-system-type)
 * [source-embed-style](#source-embed-style)
-* [target](#target)
+* [target](#target-1)
 * [stage](#stage)
 * [vulkan-shift](#vulkan-shift)
 * [capability](#capability)
 * [file-extension](#file-extension)
 * [help-category](#help-category)
 
-<a id="General"></a>
+<a id="general"></a>
 ## General
 
 General options 
 
-<a id="D"></a>
+<a id="d"></a>
 ### -D
 
 **-D&lt;name&gt;\[=&lt;value&gt;\], -D &lt;name&gt;\[=&lt;value&gt;\]**
@@ -108,7 +108,7 @@ Print this message, or help in specified category.
 Help formatting style 
 
 
-<a id="I"></a>
+<a id="i"></a>
 ### -I
 
 **-I&lt;path&gt;, -I &lt;path&gt;**
@@ -174,7 +174,7 @@ Set the module name to use when compiling multiple .slang source files into a si
 
 Specify a path where generated output should be written. 
 
-If no [-target](#target-1) or [-stage](#stage-1) is specified, one may be inferred from file extension (see [&lt;file-extension&gt;](#file-extension)). If multiple [-target](#target-1) options and a single [-entry](#entry) are present, each [-o](#o) associates with the first [-target](#target-1) to its left. Otherwise, if multiple [-entry](#entry) options are present, each [-o](#o) associates with the first [-entry](#entry) to its left, and with the [-target](#target-1) that matches the one inferred from &lt;path&gt;. 
+If no [-target](#target-2) or [-stage](#stage-1) is specified, one may be inferred from file extension (see [&lt;file-extension&gt;](#file-extension)). If multiple [-target](#target-2) options and a single [-entry](#entry) are present, each [-o](#o) associates with the first [-target](#target-2) to its left. Otherwise, if multiple [-entry](#entry) options are present, each [-o](#o) associates with the first [-entry](#entry) to its left, and with the [-target](#target-2) that matches the one inferred from &lt;path&gt;. 
 
 
 <a id="profile"></a>
@@ -196,7 +196,7 @@ Additional profiles that include [-stage](#stage-1) information:
 
 See [-capability](#capability-1) for information on [&lt;capability&gt;](#capability) 
 
-When multiple [-target](#target-1) options are present, each [-profile](#profile) associates with the first [-target](#target-1) to its left. 
+When multiple [-target](#target-2) options are present, each [-profile](#profile) associates with the first [-target](#target-2) to its left. 
 
 
 <a id="stage-1"></a>
@@ -211,10 +211,10 @@ When multiple [-entry](#entry) options are present, each [-stage](#stage-1) asso
 May be omitted if entry-point function has a \[shader(...)\] attribute; otherwise required for each [-entry](#entry) option. 
 
 
-<a id="target-1"></a>
+<a id="target-2"></a>
 ### -target
 
-**-target &lt;[target](#target)&gt;**
+**-target &lt;[target](#target-1)&gt;**
 
 Specifies the format in which code should be generated. 
 
@@ -254,15 +254,15 @@ all - Treat all warnings as errors.
 Disable specific warning ids. 
 
 
-<a id="W"></a>
+<a id="w"></a>
 ### -W
 
 **-W&lt;id&gt;**
 
 Enable a warning with the specified id. 
 
 
-<a id="Wno"></a>
+<a id="wno"></a>
 ### -Wno-
 
 **-Wno-&lt;id&gt;**
@@ -377,7 +377,7 @@ Pack bitfields according to MSVC rules (msb first, new field when underlying typ
 
 
 
-<a id="Target"></a>
+<a id="target"></a>
 ## Target
 
 Target code generation options 
@@ -461,7 +461,7 @@ Sets how the `#line` directives should be produced. Available options are:
 If not specified, default behavior is to use C-style `#line` directives for HLSL and C/C++ output, and traditional GLSL-style `#line` directives for GLSL output. 
 
 
-<a id="O"></a>
+<a id="o-1"></a>
 ### -O
 
 **-O&lt;[optimization-level](#optimization-level)&gt;**
@@ -615,7 +615,7 @@ Sets a comma-separates list of architecture-specific features for the LLVM targe
 
 
 
-<a id="Downstream"></a>
+<a id="downstream"></a>
 ## Downstream
 
 Downstream compiler options 
@@ -638,12 +638,12 @@ Specify path to a downstream [&lt;compiler&gt;](#compiler) executable or library
 Set a default compiler for the given language. See [-lang](#lang) for the list of languages. 
 
 
-<a id="X"></a>
+<a id="x"></a>
 ### -X
 
 **-X&lt;[compiler](#compiler)&gt; &lt;option&gt; -X&lt;[compiler](#compiler)&gt;... &lt;options&gt; -X.**
 
-Pass arguments to downstream [&lt;compiler&gt;](#compiler). Just [-X&lt;compiler&gt;](#X) passes just the next argument to the downstream compiler. [-X&lt;compiler&gt;](#X)... options [-X](#X). will pass *all* of the options inbetween the opening [-X](#X) and [-X](#X). to the downstream compiler. 
+Pass arguments to downstream [&lt;compiler&gt;](#compiler). Just [-X&lt;compiler&gt;](#x) passes just the next argument to the downstream compiler. [-X&lt;compiler&gt;](#x)... options [-X](#x). will pass *all* of the options inbetween the opening [-X](#x) and [-X](#x). to the downstream compiler. 
 
 
 <a id="pass-through"></a>
@@ -657,7 +657,7 @@ These are intended for debugging/testing purposes, when you want to be able to s
 
 
 
-<a id="Debugging"></a>
+<a id="debugging"></a>
 ## Debugging
 
 Compiler debugging/instrumentation options 
@@ -690,7 +690,7 @@ Dump the IR after every pass for debugging.
 Dump the IDs with [-dump-ir](#dump-ir) (debug builds only) 
 
 
-<a id="E"></a>
+<a id="e"></a>
 ### -E, -output-preprocessor
 Output the preprocessing result and exit. 
 
@@ -767,7 +767,7 @@ Print the minimum and maximum module versions this compiler supports
 
 
 
-<a id="Repro"></a>
+<a id="repro"></a>
 ## Repro
 
 Slang repro system related 
@@ -827,7 +827,7 @@ There are two *special* directories:
 
 
 
-<a id="Experimental"></a>
+<a id="experimental"></a>
 ## Experimental
 
 Experimental options (use at your own risk) 
@@ -909,7 +909,7 @@ Control colored diagnostic output (auto uses color if stderr is a tty)
 
 
 
-<a id="Internal"></a>
+<a id="internal"></a>
 ## Internal
 
 Internal-use options (use at your own risk) 
@@ -1002,7 +1002,7 @@ Generate code for all entry points in a single output (library mode).
 
 
 
-<a id="Deprecated"></a>
+<a id="deprecated"></a>
 ## Deprecated
 
 Deprecated options (allowed but ignored; may be removed in future) 
@@ -1162,7 +1162,7 @@ Source Embed Style
 * `u32` : Embed as uint32_t. 
 * `u64` : Embed as uint64_t. 
 
-<a id="target"></a>
+<a id="target-1"></a>
 ## target
 
 Target 

source/core/slang-command-options-writer.cpp

@@ -440,7 +440,10 @@ UnownedStringSlice MarkdownCommandOptionsWriter::_getLinkName(const NameKey& key
     }
 
     StringBuilder buf;
-    buf << prefix;
+    for (char c : prefix)
+    {
+        buf.append(CharUtil::toLower(c));
+    }
 
     const auto bufLen = buf.getLength();