[llvm] Handle CPI symbols for UEFI

UEFI targets besides MSVC environment must support constant pool
symbols.

Author: Prabhuk

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

@@ -4096,7 +4096,8 @@ const MCExpr *AsmPrinter::lowerBlockAddressConstant(const BlockAddress &BA) {
 
 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
-  if (getSubtargetInfo().getTargetTriple().isWindowsMSVCEnvironment()) {
+  if (getSubtargetInfo().getTargetTriple().isWindowsMSVCEnvironment() ||
+      getSubtargetInfo().getTargetTriple().isUEFI()) {
     const MachineConstantPoolEntry &CPE =
         MF->getConstantPool()->getConstants()[CPID];
     if (!CPE.isMachineConstantPoolEntry()) {