Return something (i.e. NULL) from an unimplemented virtual function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58183 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Target/TargetJITInfo.h

@@ -100,6 +100,7 @@ namespace llvm {
     /// meaningful to the target.
     virtual char* allocateThreadLocalMemory(size_t size) {
       assert(0 && "This target does not implement thread local storage!");
+      return 0;
     }
 
     /// needsGOT - Allows a target to specify that it would like the