[emacs] Handle vector types, arbitary integer types and function names (#88246)

Resurrecting this patch from https://reviews.llvm.org/D158321

This adds a few more regexp patterns for llvm-mode-syntax-table. The
primitive type regexp was split out so it could be reused when handling
vectors. Also worth noting is that the vector regexp needs to come
before the primitive types, otherwise they will match first.

Author: lukel97

llvm/utils/emacs/llvm-mode.el

@@ -18,6 +18,14 @@
     table)
   "Syntax table used while in LLVM mode.")
 
+(defconst llvm-mode-primitive-type-regexp
+  (concat
+   "\\(i[0-9]+\\|"
+   (regexp-opt
+    '("void" "half" "bfloat" "float" "double" "fp128" "x86_fp80" "ppc_fp128"
+      "x86_mmx" "x86_amx" "ptr" "type" "label" "opaque" "token") t)
+   "\\)"))
+
 (defvar llvm-font-lock-keywords
   (list
    ;; Attributes
@@ -34,10 +42,23 @@
    '("[-a-zA-Z$._0-9]+:" . font-lock-variable-name-face)
    ;; Unnamed variable slots
    '("%[-]?[0-9]+" . font-lock-variable-name-face)
-   ;; Types
-   `(,(regexp-opt
-       '("void" "i1" "i8" "i16" "i32" "i64" "i128" "half" "bfloat" "float" "double" "fp128" "x86_fp80" "ppc_fp128" "x86_mmx" "x86_amx" "ptr"
-         "type" "label" "opaque" "token") 'symbols) . font-lock-type-face)
+   ;; Function names
+   '("@[-a-zA-Z$._][-a-zA-Z$._0-9]*" . font-lock-function-name-face)
+   ;; Fixed vector types
+   `(,(concat "<[ \t]*\\([0-9]+\\)[ \t]*x[ \t]+"
+	      llvm-mode-primitive-type-regexp
+	      "[ \t]*>")
+     (1 'font-lock-type-face)
+     (2 'font-lock-type-face))
+   ;; Scalable vector types
+   `(,(concat "<[ \t]*\\(vscale[ \t]\\)+x[ \t]+\\([0-9]+\\)[ \t]*x[ \t]+"
+	      llvm-mode-primitive-type-regexp
+	      "[ \t]*>")
+     (1 'font-lock-keyword-face)
+     (2 'font-lock-type-face)
+     (3 'font-lock-type-face))
+   ;; Primitive types
+   `(,(concat "\\<" llvm-mode-primitive-type-regexp "\\>") . font-lock-type-face)
    ;; Integer literals
    '("\\b[-]?[0-9]+\\b" . font-lock-preprocessor-face)
    ;; Floating point constants