Silence some MSVC warnings.

Summary:
Just `assert("string" && false)` instead of `assert("string" == NULL)`.

This avoid errors like

    [...]\Core\SourceManager.cpp(647): warning C4130: '==' : logical operation on address of string constant

Reviewers: zturner

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D12388

llvm-svn: 246123

Author: sas

lldb/source/Core/SourceManager.cpp

@@ -644,14 +644,14 @@ SourceManager::File::CalculateLineOffsets (uint32_t line)
         else
         {
             // Some lines have been populated, start where we last left off
-            assert("Not implemented yet" == NULL);
+            assert("Not implemented yet" && false);
         }
 
     }
     else
     {
         // Calculate all line offsets up to "line"
-        assert("Not implemented yet" == NULL);
+        assert("Not implemented yet" && false);
     }
     return false;
 }