[AMDGPU] Don't use emitFunctionEntryLabel() from the base AsmPrinter

[rochauha]

Summary

AMDGPUAsmPrinter::emitFunctionEntryLabel() relies on the base implementation to actually emit the function entry label.
AMDGPU kernel symbols have global binding. The base implementation tends to add another local symbol in such a case, which is unwanted.

[arsenm]

Needs test

llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp

getTargetStreamer()->EmitAmdhsaKernelDescriptor(
       hasXNACK(STI));
 
   Streamer.PopSection();
 }
 
 void AMDGPUAsmPrinter::emitFunctionEntryLabel() {
   if (IsaInfo::hasCodeObjectV3(getGlobalSTI()) &&
       TM.getTargetTriple().getOS() == Triple::AMDHSA) {
-    AsmPrinter::emitFunctionEntryLabel();
+    MCSymbol *Sym = getSymbol(&MF->getFunction());
+    OutStreamer->emitLabel(Sym);
     return;
   }
 
   const SIMachineFunctionInfo *MFI = MF->getInfo<SIMachineFunctionInfo>();
   const GCNSubtarget &STM = MF->getSubtarget<GCNSubtarget>();
   if (MFI->isEntryFunction() && STM.isAmdHsaOrMesa(MF->getFunction())) {
     SmallString<128> SymbolName;
     getNameWithPrefix(SymbolName, &MF->getFunction()),
     getTargetStreamer()->EmitAMDGPUSymbolType(
         SymbolName, ELF::STT_AMDGPU_HSA_KERNEL);
   }
   if (DumpCodeInstEmitter) {
     // Disassemble function name label to text.
     DisasmLines.push_back(MF->getName().str() + ":");
     DisasmLineMaxLen = std::max(DisasmLineMaxLen, DisasmLines.back().size());
     HexLines.push_back("");
   }
 
-  AsmPrinter::emitFunctionEntryLabel();
+  MCSymbol *Sym = getSymbol(&MF->getFunction());
+  OutStreamer->emitLabel(Sym);
 }
 
 void AMDGPUAsmPrinter::emitBasicBlockStart(const MachineBasicBlock &MBB) {
   if (DumpCodeInstEmitter && !isBlockOnlyReachableByFallthrough(&MBB)) {
     // Write a line for the basic block label if it is not only fallthrough.
     DisasmLines.push_back(
         (Twine("BB") + Twine(getFunctionNumber())
          + "_" + Twine(MBB.getNumber()) + ":").str());