[llvm] Linker flags for UEFI

Use appropriate linker flag format to match PE spec for UEFI.

Author: Prabhuk

llvm/lib/IR/Mangler.cpp

@@ -215,15 +215,15 @@ void llvm::emitLinkerFlagsForGlobalCOFF(raw_ostream &OS, const GlobalValue *GV,
                                         const Triple &TT, Mangler &Mangler) {
   if (GV->hasDLLExportStorageClass() && !GV->isDeclaration()) {
 
-    if (TT.isWindowsMSVCEnvironment())
+    if (TT.isWindowsMSVCEnvironment() || TT.isUEFI())
       OS << " /EXPORT:";
     else
       OS << " -export:";
 
     bool NeedQuotes = GV->hasName() && !canBeUnquotedInDirective(GV->getName());
     if (NeedQuotes)
       OS << "\"";
-    if (TT.isWindowsGNUEnvironment() || TT.isWindowsCygwinEnvironment()) {
+    if (TT.isWindowsGNUEnvironment() || TT.isWindowsCygwinEnvironment() || TT.isUEFI()) {
       std::string Flag;
       raw_string_ostream FlagOS(Flag);
       Mangler.getNameWithPrefix(FlagOS, GV, false);
@@ -249,7 +249,7 @@ void llvm::emitLinkerFlagsForGlobalCOFF(raw_ostream &OS, const GlobalValue *GV,
       OS << "\"";
 
     if (!GV->getValueType()->isFunctionTy()) {
-      if (TT.isWindowsMSVCEnvironment())
+      if (TT.isWindowsMSVCEnvironment() || TT.isUEFI())
         OS << ",DATA";
       else
         OS << ",data";