[IPSCCP] Variable not visible at Og:

https://bugs.llvm.org/show_bug.cgi?id=51559
#50901

IPSCCP pass removes the global variable and does not
create a constant expression for the initializer value.

Fix assertion detected by the BuildKite pre-commit CI:

llvm::APInt::getZExtValue() const:
`getActiveBits() <= 64 && "Too many bits for uint64_t"' failed.

Author: CarlosAlbertoEnciso

llvm/lib/Transforms/Utils/Local.cpp

@@ -3588,8 +3588,12 @@ DIExpression *llvm::getExpressionForConstant(DIBuilder &DIB, const Constant &C,
   auto *FP = dyn_cast<ConstantFP>(&C);
   if (FP && Ty.isFloatingPointTy()) {
     const APFloat &APF = FP->getValueAPF();
-    return DIB.createConstantValueExpression(
-        APF.bitcastToAPInt().getZExtValue());
+    APInt const &API = APF.bitcastToAPInt();
+    if (auto Temp = API.tryZExtValue())
+      return DIB.createConstantValueExpression(static_cast<uint64_t>(*Temp));
+    else if (auto Temp = API.trySExtValue())
+      return DIB.createConstantValueExpression(static_cast<uint64_t>(*Temp));
+    return DIB.createConstantValueExpression(*API.getRawData());
   }
 
   if (!Ty.isPointerTy())