constify some stuff



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@41503 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/AST/ASTContext.cpp b/AST/ASTContext.cpp
index 1a740b5..bc73748 100644
--- a/AST/ASTContext.cpp
+++ b/AST/ASTContext.cpp
@@ -314,8 +314,8 @@
 
 /// getEnumDeclIntegerType - returns the integer type compatible with the
 /// given enum type.
-QualType ASTContext::getEnumDeclIntegerType(EnumDecl *ED) const {
-  if (EnumConstantDecl *C = ED->getEnumConstantList())
+QualType ASTContext::getEnumDeclIntegerType(const EnumDecl *ED) const {
+  if (const EnumConstantDecl *C = ED->getEnumConstantList())
     return C->getType();
 
   // If the enum list is empty, it is typed as if it contained a single zero