llvm-undname: Several behavior-preserving changes to increase coverage

- Replace `Error = true` in a few branches that are truly unreachable
  with DEMANGLE_UNREACHABLE

- Remove early return early in startsWithLocalScopePattern() because
  it's redundant with the next two early returns

- Remove unreachable `case '0'` (it's handled in the branch below)

- Remove an unused bool return

- Add test coverage for several early error returns, mostly in
  array type parsing

llvm-svn: 362506

1 files changed, 4 insertions, 5 deletions

diff --git a/llvm/lib/Demangle/MicrosoftDemangleNodes.cpp b/llvm/lib/Demangle/MicrosoftDemangleNodes.cpp
index c26151c5b19..c07fde897e0 100644
--- a/llvm/lib/Demangle/MicrosoftDemangleNodes.cpp
+++ b/llvm/lib/Demangle/MicrosoftDemangleNodes.cpp
@@ -34,21 +34,20 @@ static void outputSpaceIfNecessary(OutputStream &OS) {
     OS << " ";
 }
 
-static bool outputSingleQualifier(OutputStream &OS, Qualifiers Q) {
+static void outputSingleQualifier(OutputStream &OS, Qualifiers Q) {
   switch (Q) {
   case Q_Const:
     OS << "const";
-    return true;
+    break;
   case Q_Volatile:
     OS << "volatile";
-    return true;
+    break;
   case Q_Restrict:
     OS << "__restrict";
-    return true;
+    break;
   default:
     break;
   }
-  return false;
 }
 
 static bool outputQualifierIfPresent(OutputStream &OS, Qualifiers Q,