[Mips,MC] Replace getSymA()->getSymbol() with getAddSym. NFC

We will replace the MCSymbolRefExpr member in MCValue with MCSymbol.
This change reduces dependence on MCSymbolRefExpr.

Create a MipsMCExpr::create overload that takes MCSymbol as an argument.
We use the order preferred by other targets.

Author: MaskRay

llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp

@@ -3009,7 +3009,7 @@ bool MipsAsmParser::loadAndAddSymbolAddress(const MCExpr *SymExpr,
       const MCExpr *CallHiExpr =
           MipsMCExpr::create(MipsMCExpr::MEK_GOT_HI16, SymExpr, getContext());
       const MCExpr *CallLoExpr = MipsMCExpr::create(
-          MipsMCExpr::MEK_GOT_LO16, Res.getSymA(), getContext());
+          Res.getAddSym(), MipsMCExpr::MEK_GOT_LO16, getContext());
 
       TOut.emitRX(Mips::LUi, TmpReg, MCOperand::createExpr(CallHiExpr), IDLoc,
                   STI);
@@ -3040,7 +3040,7 @@ bool MipsAsmParser::loadAndAddSymbolAddress(const MCExpr *SymExpr,
       // The daddiu's marked with a '>' may be omitted if they are redundant. If
       // this happens then the last instruction must use $rd as the result
       // register.
-      GotExpr = MipsMCExpr::create(MipsMCExpr::MEK_GOT_DISP, Res.getSymA(),
+      GotExpr = MipsMCExpr::create(Res.getAddSym(), MipsMCExpr::MEK_GOT_DISP,
                                    getContext());
       if (Res.getConstant() != 0) {
         // Symbols fully resolve with just the %got_disp(symbol) but we
@@ -3075,7 +3075,7 @@ bool MipsAsmParser::loadAndAddSymbolAddress(const MCExpr *SymExpr,
         // External symbols fully resolve the symbol with just the %got(symbol)
         // but we must still account for any offset to the symbol for
         // expressions like symbol+8.
-        GotExpr = MipsMCExpr::create(MipsMCExpr::MEK_GOT, Res.getSymA(),
+        GotExpr = MipsMCExpr::create(Res.getAddSym(), MipsMCExpr::MEK_GOT,
                                      getContext());
         if (Res.getConstant() != 0)
           LoExpr = MCConstantExpr::create(Res.getConstant(), getContext());
@@ -3771,8 +3771,9 @@ void MipsAsmParser::expandMem16Inst(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out,
         return;
       }
 
-      loadAndAddSymbolAddress(Res.getSymA(), TmpReg, BaseReg,
-                              !ABI.ArePtrs64bit(), IDLoc, Out, STI);
+      loadAndAddSymbolAddress(
+          MCSymbolRefExpr::create(Res.getAddSym(), getContext()), TmpReg,
+          BaseReg, !ABI.ArePtrs64bit(), IDLoc, Out, STI);
       emitInstWithOffset(MCOperand::createImm(int16_t(Res.getConstant())));
     } else {
       // FIXME: Implement 64-bit case.

llvm/lib/Target/Mips/MCTargetDesc/MipsMCExpr.cpp

@@ -26,7 +26,12 @@ using namespace llvm;
 
 const MipsMCExpr *MipsMCExpr::create(MipsMCExpr::Specifier S,
                                      const MCExpr *Expr, MCContext &Ctx) {
-  return new (Ctx) MipsMCExpr(S, Expr);
+  return new (Ctx) MipsMCExpr(Expr, S);
+}
+
+const MipsMCExpr *MipsMCExpr::create(const MCSymbol *Sym, Specifier S,
+                                     MCContext &Ctx) {
+  return new (Ctx) MipsMCExpr(MCSymbolRefExpr::create(Sym, Ctx), S);
 }
 
 const MipsMCExpr *MipsMCExpr::createGpOff(MipsMCExpr::Specifier S,

llvm/lib/Target/Mips/MCTargetDesc/MipsMCExpr.h

@@ -47,15 +47,17 @@ class MipsMCExpr : public MCTargetExpr {
   };
 
 private:
-  const Specifier specifier;
   const MCExpr *Expr;
+  const Specifier specifier;
 
-  explicit MipsMCExpr(Specifier S, const MCExpr *Expr)
-      : specifier(S), Expr(Expr) {}
+  explicit MipsMCExpr(const MCExpr *Expr, Specifier S)
+      : Expr(Expr), specifier(S) {}
 
 public:
   static const MipsMCExpr *create(Specifier S, const MCExpr *Expr,
                                   MCContext &Ctx);
+  static const MipsMCExpr *create(const MCSymbol *Sym, Specifier S,
+                                  MCContext &Ctx);
   static const MipsMCExpr *createGpOff(Specifier S, const MCExpr *Expr,
                                        MCContext &Ctx);