Wherein the TargetInfo argument to Preprocessor is made 'const' and propogated.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@87087 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 0add7e6..7aa3418 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -35,7 +35,7 @@
 };
 
 ASTContext::ASTContext(const LangOptions& LOpts, SourceManager &SM,
-                       TargetInfo &t,
+                       const TargetInfo &t,
                        IdentifierTable &idents, SelectorTable &sels,
                        Builtin::Context &builtins,
                        bool FreeMem, unsigned size_reserve) :