[MCJIT] Set VMA to code address in PerfJITEventListener.

VMA should default to CodeAddr, not 0, as specified here:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/perf/Documentation/jitdump-specification.txt

Reviewed By: lhames

Differential Revision: https://reviews.llvm.org/D146496

(cherry picked from commit e5bdf0f)

Author: pchintalapudi

llvm/lib/ExecutionEngine/PerfJITEvents/PerfJITEventListener.cpp

@@ -417,7 +417,7 @@ void PerfJITEventListener::NotifyCode(Expected<llvm::StringRef> &Symbol,
   rec.Prefix.Timestamp = perf_get_timestamp();
 
   rec.CodeSize = CodeSize;
-  rec.Vma = 0;
+  rec.Vma = CodeAddr;
   rec.CodeAddr = CodeAddr;
   rec.Pid = Pid;
   rec.Tid = get_threadid();