[XCOFF][AIX] Differentiate usage of label symbol and csect symbol

Summary:
 We are using symbols to represent label and csect interchangeably before, and that could be a problem.
There are cases we would need to add storage mapping class to the symbol if that symbol is actually the name of a csect, but it's hard for us to figure out whether that symbol is a label or csect.

This patch intend to do the following:
    1. Construct a QualName (A name include the storage mapping class)
       MCSymbolXCOFF for every MCSectionXCOFF.
    2. Keep a pointer to that QualName inside of MCSectionXCOFF.
    3. Use that QualName whenever we need a symbol refers to that
       MCSectionXCOFF.
    4. Adapt the snowball effect from the above changes in
       XCOFFObjectWriter.cpp.

Reviewers: xingxue, DiggerLin, sfertile, daltenty, hubert.reinterpretcast

Reviewed By: DiggerLin, daltenty

Subscribers: wuzish, nemanjai, mgorny, hiraditya, kbarton, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69633

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/MC/MCAsmInfo.cpp b/llvm/lib/MC/MCAsmInfo.cpp
index 71e51e320f8..420dbaa80ae 100644
--- a/llvm/lib/MC/MCAsmInfo.cpp
+++ b/llvm/lib/MC/MCAsmInfo.cpp
@@ -100,7 +100,7 @@ MCAsmInfo::getExprForFDESymbol(const MCSymbol *Sym,
   return MCBinaryExpr::createSub(Res, PC, Context);
 }
 
-static bool isAcceptableChar(char C) {
+bool MCAsmInfo::isAcceptableChar(char C) const {
   return (C >= 'a' && C <= 'z') || (C >= 'A' && C <= 'Z') ||
          (C >= '0' && C <= '9') || C == '_' || C == '$' || C == '.' || C == '@';
 }