Make these methods const correct.

Thanks to Nick Lewycky for noticing it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187098 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/IR/Module.cpp b/lib/IR/Module.cpp
index 3d3dc73..968b8f4 100644
--- a/lib/IR/Module.cpp
+++ b/lib/IR/Module.cpp
@@ -233,8 +233,7 @@
 /// If AllowLocal is set to true, this function will return types that
 /// have an local. By default, these types are not returned.
 ///
-GlobalVariable *Module::getGlobalVariable(StringRef Name,
-                                          bool AllowLocal) const {
+GlobalVariable *Module::getGlobalVariable(StringRef Name, bool AllowLocal) {
   if (GlobalVariable *Result =
       dyn_cast_or_null<GlobalVariable>(getNamedValue(Name)))
     if (AllowLocal || !Result->hasLocalLinkage())