Inline deprecated CallBase::getCalledValue

This function has already been removed on upstream LLVM. Inlining it
here fixes a compile issue on `master-next`.

Author: MForster

lib/IRGen/GenCall.cpp

@@ -1615,7 +1615,7 @@ llvm::CallInst *CallEmission::emitCallSite() {
 
     // Insert a call to @llvm.coro.prepare.retcon, then bitcast to the right
     // function type.
-    auto origCallee = call->getCalledValue();
+    auto origCallee = call->getCalledOperand();
     llvm::Value *opaqueCallee = origCallee;
     opaqueCallee =
       IGF.Builder.CreateBitCast(opaqueCallee, IGF.IGM.Int8PtrTy);

lib/LLVMPasses/LLVMMergeFunctions.cpp

@@ -1078,7 +1078,7 @@ bool SwiftMergeFunctions::replaceDirectCallers(Function *Old, Function *New,
       removeEquivalenceClassFromTree(FE);
 
     auto *CI = dyn_cast<CallInst>(I);
-    if (!CI || CI->getCalledValue() != Old) {
+    if (!CI || CI->getCalledOperand() != Old) {
       AllReplaced = false;
       continue;
     }