[CSSPGO] Emit mangled dwarf names for line tables debug option under -fpseudo-probe-for-profiling

[wenlei]

lgtm, thanks for the fix.

clang/lib/CodeGen/CGDebugInfo.cpp

if (FD->hasPrototype()) {
     Flags |= llvm::DINode::FlagPrototyped;
   }
   // No need to replicate the linkage name if it isn't different from the
   // subprogram name, no need to have it at all unless coverage is enabled or
   // debug is set to more than just line tables or extra debug info is needed.
   if (LinkageName == Name || (!CGM.getCodeGenOpts().EmitGcovArcs &&
                               !CGM.getCodeGenOpts().EmitGcovNotes &&
                               !CGM.getCodeGenOpts().DebugInfoForProfiling &&
+                              !CGM.getCodeGenOpts().PseudoProbeForProfiling &&
                               DebugKind <= codegenoptions::DebugLineTablesOnly))
     LinkageName = StringRef();
 
   // Emit the function scope in line tables only mode (if CodeView) to
   // differentiate between function names.
   if (CGM.getCodeGenOpts().hasReducedDebugInfo() ||
       (DebugKind == codegenoptions::DebugLineTablesOnly &&
        CGM.getCodeGenOpts().EmitCodeView)) {

clang/test/CodeGen/debug-info-pseudo-probe.cpp

+// This test checks if a symbol gets mangled dwarf names with -fpseudo-probe-for-profiling option.
+// RUN: %clang_cc1 -triple x86_64 -x c++ -S -emit-llvm -debug-info-kind=line-tables-only -o - < %s | FileCheck %s --check-prefix=PLAIN
+// RUN: %clang_cc1 -triple x86_64 -x c++  -S -emit-llvm -debug-info-kind=line-tables-only -fpseudo-probe-for-profiling -o - < %s | FileCheck %s --check-prefix=MANGLE
+
+int foo() {
+  return 0;
+}
+
+// PLAIN: define dso_local i32 @_Z3foov()
+// PLAIN: distinct !DISubprogram(name: "foo", scope:
+// MANGLE: define dso_local i32 @_Z3foov()
+// MANGLE: distinct !DISubprogram(name: "foo", linkageName: "_Z3foov"