Clean up warnings after a2c8cd1

Author: d0k

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

@@ -397,6 +397,7 @@ void AsmPrinter::emitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
   case GlobalValue::CommonLinkage:
     assert(!TM.getTargetTriple().isOSBinFormatXCOFF() &&
            "CommonLinkage of XCOFF should not come to this path.");
+    LLVM_FALLTHROUGH;
   case GlobalValue::LinkOnceAnyLinkage:
   case GlobalValue::LinkOnceODRLinkage:
   case GlobalValue::WeakAnyLinkage:

llvm/lib/MC/MCELFStreamer.cpp

@@ -203,6 +203,7 @@ bool MCELFStreamer::emitSymbolAttribute(MCSymbol *S, MCSymbolAttr Attribute) {
   // defined.
   switch (Attribute) {
   case MCSA_Cold:
+  case MCSA_Extern:
   case MCSA_LazyReference:
   case MCSA_Reference:
   case MCSA_SymbolResolver:

llvm/lib/MC/MCMachOStreamer.cpp

@@ -326,6 +326,7 @@ bool MCMachOStreamer::emitSymbolAttribute(MCSymbol *Sym,
   case MCSA_ELF_TypeCommon:
   case MCSA_ELF_TypeNoType:
   case MCSA_ELF_TypeGnuUniqueObject:
+  case MCSA_Extern:
   case MCSA_Hidden:
   case MCSA_IndirectSymbol:
   case MCSA_Internal: