[SYCL][NFC] Fix static code analysis concerns (#4932)

Found via a static-analysis tool:
Pointer may be dereferenced after it was positively checked for NULL

Inside GenerateCode() function:

if (FD->isInlineBuiltinDeclaration() && Fn) {} ----> Pointer 'Fn' checked for NULL here

if (SyclOptReport.HasOptReportInfo(FD)) {
llvm::OptimizationRemarkEmitter ORE(Fn); ---> Pointer 'Fn' is dereferenced by passing argument 1 to function "OptimizationRemarkEmitter"

This patch checks Pointer 'Fn' inside routine to resolve the bug.

Signed-off-by: Soumi Manna [email protected]

Author: smanna12

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -1540,7 +1540,7 @@ void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn,
   StartFunction(GD, ResTy, Fn, FnInfo, Args, Loc, BodyRange.getBegin());
 
   SyclOptReportHandler &SyclOptReport = CGM.getDiags().getSYCLOptReport();
-  if (SyclOptReport.HasOptReportInfo(FD)) {
+  if (Fn && SyclOptReport.HasOptReportInfo(FD)) {
     llvm::OptimizationRemarkEmitter ORE(Fn);
     for (auto ORI : llvm::enumerate(SyclOptReport.GetInfo(FD))) {
       llvm::DiagnosticLocation DL =