De-ASTContext-ify DeclContext.

Remove ASTContext parameter from DeclContext's methods. This change cascaded down to other Decl's methods and changes to call sites started "escalating".
Timings using pre-tokenized "cocoa.h" showed only a ~1% increase in time run between and after this commit.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@74506 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaInherit.cpp b/lib/Sema/SemaInherit.cpp
index 28ca5f6..2f914f1 100644
--- a/lib/Sema/SemaInherit.cpp
+++ b/lib/Sema/SemaInherit.cpp
@@ -187,7 +187,7 @@
         = (Context.getCanonicalType(BaseSpec->getType()) == Criteria.Base);
       break;
     case MemberLookupCriteria::LK_NamedMember:
-      Paths.ScratchPath.Decls = BaseRecord->lookup(Context, Criteria.Name);
+      Paths.ScratchPath.Decls = BaseRecord->lookup(Criteria.Name);
       while (Paths.ScratchPath.Decls.first != Paths.ScratchPath.Decls.second) {
         if (isAcceptableLookupResult(*Paths.ScratchPath.Decls.first,
                                      Criteria.NameKind, Criteria.IDNS)) {
@@ -199,7 +199,7 @@
       break;
     case MemberLookupCriteria::LK_OverriddenMember:
       Paths.ScratchPath.Decls = 
-        BaseRecord->lookup(Context, Criteria.Method->getDeclName());
+        BaseRecord->lookup(Criteria.Method->getDeclName());
       while (Paths.ScratchPath.Decls.first != Paths.ScratchPath.Decls.second) {
         if (CXXMethodDecl *MD = 
               dyn_cast<CXXMethodDecl>(*Paths.ScratchPath.Decls.first)) {