Make assert() message more informative.

PR11217.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142956 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
index 90501f0..268584c 100644
--- a/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -121,7 +121,8 @@
   // we'll crash later.
   // Provide the user with a useful error message about what's wrong.
   assert(AsmInfo && "MCAsmInfo not initialized."
-	 "Make sure you include the correct TargetSelect.h!");
+         "Make sure you include the correct TargetSelect.h"
+         "and that InitializeAllTargetMCs() is being invoked!");
 }
 
 bool LLVMTargetMachine::addPassesToEmitFile(PassManagerBase &PM,