[llvm-symbolizer] - Fix the crash in GNU output style with --no-inlines and missing input file.

Fixes https://bugs.llvm.org/show_bug.cgi?id=48882.

If the input file does not exist (or has a reading error), the
following code will crash if there are two or more input addresses.

```
auto ResOrErr = Symbolizer.symbolizeInlinedCode(
  ModuleName, {Offset, object::SectionedAddress::UndefSection});
Printer << (error(ResOrErr) ? DILineInfo() : ResOrErr.get().getFrame(0));
```

For the first address, `symbolizeInlinedCode` returns an error.
For the second address, `symbolizeInlinedCode` returns an empty result
(not an error) and `.getFrame(0)` will crash.

Differential revision: https://reviews.llvm.org/D95609

(cherry picked from commit d221406)

Author: Georgii Rymar

llvm/test/tools/llvm-symbolizer/output-style-inlined.test

@@ -28,3 +28,24 @@ RUN:   | FileCheck %s --check-prefix=LLVM --implicit-check-not=inctwo
 
 LLVM: main
 GNU: inctwo
+
+## Check that we are able to produce an output properly when the --no-inlines option
+## is specified, but a file doesn't exist. Check we report an error.
+
+RUN: llvm-symbolizer --output-style=GNU --obj=%p/Inputs/not.exist 0x1 0x2 --no-inlines 2>&1 \
+RUN:   | FileCheck %s --check-prefix=NOT-EXIST-GNU -DMSG=%errc_ENOENT
+RUN: llvm-symbolizer --output-style=LLVM --obj=%p/Inputs/not.exist 0x1 0x2 --no-inlines 2>&1 \
+RUN:   | FileCheck %s --check-prefix=NOT-EXIST-LLVM -DMSG=%errc_ENOENT
+
+# NOT-EXIST-GNU:      LLVMSymbolizer: error reading file: [[MSG]]
+# NOT-EXIST-GNU-NEXT: ??
+# NOT-EXIST-GNU-NEXT: ??:0
+# NOT-EXIST-GNU-NEXT: ??
+# NOT-EXIST-GNU-NEXT: ??:0
+
+# NOT-EXIST-LLVM:       LLVMSymbolizer: error reading file: [[MSG]]
+# NOT-EXIST-LLVM-NEXT:  ??
+# NOT-EXIST-LLVM-NEXT:  ??:0:0
+# NOT-EXIST-LLVM-EMPTY:
+# NOT-EXIST-LLVM-NEXT:  ??
+# NOT-EXIST-LLVM-NEXT:  ??:0:0

llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp

@@ -181,7 +181,12 @@ static void symbolizeInput(const opt::InputArgList &Args, uint64_t AdjustVMA,
     // the topmost function, which suits our needs better.
     auto ResOrErr = Symbolizer.symbolizeInlinedCode(
         ModuleName, {Offset, object::SectionedAddress::UndefSection});
-    Printer << (error(ResOrErr) ? DILineInfo() : ResOrErr.get().getFrame(0));
+    if (!ResOrErr || ResOrErr->getNumberOfFrames() == 0) {
+      error(ResOrErr);
+      Printer << DILineInfo();
+    } else {
+      Printer << ResOrErr->getFrame(0);
+    }
   } else {
     auto ResOrErr = Symbolizer.symbolizeCode(
         ModuleName, {Offset, object::SectionedAddress::UndefSection});