Tweak CrashRecoveryContext::GetCurrent() to return quickly if 'gCrsah…

…RecoveryEnabled' is false. This avoids us needing to go to thread local storage for

the performance sensitive case where we are compiling code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127928 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/CrashRecoveryContext.cpp

@@ -74,6 +74,9 @@ CrashRecoveryContext::~CrashRecoveryContext() {
 }
 
 CrashRecoveryContext *CrashRecoveryContext::GetCurrent() {
+  if (!gCrashRecoveryEnabled)
+    return 0;
+
   const CrashRecoveryContextImpl *CRCI = CurrentContext.get();
   if (!CRCI)
     return 0;