[AST] Remove ASTContext from getThisType (NFC)

Summary:
https://reviews.llvm.org/D54862 removed the usages of `ASTContext&` from
within the `CXXMethodDecl::getThisType` method. Remove the parameter
altogether, as well as all usages of it. This does not result in any
functional change because the parameter was unused since
https://reviews.llvm.org/D54862.

Test Plan: check-clang

Reviewers: akyrtzi, mikael

Reviewed By: mikael

Subscribers: mehdi_amini, dexonsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D56509

llvm-svn: 350914
diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
index f91f6ed..ee150a7 100644
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -2014,7 +2014,7 @@
   CallArgList Args;
 
   LangAS SlotAS = E->getType().getAddressSpace();
-  QualType ThisType = D->getThisType(getContext());
+  QualType ThisType = D->getThisType();
   LangAS ThisAS = ThisType.getTypePtr()->getPointeeType().getAddressSpace();
   llvm::Value *ThisPtr = This.getPointer();
   if (SlotAS != ThisAS) {
@@ -2025,7 +2025,7 @@
                                                     ThisAS, SlotAS, NewType);
   }
   // Push the this ptr.
-  Args.add(RValue::get(ThisPtr), D->getThisType(getContext()));
+  Args.add(RValue::get(ThisPtr), D->getThisType());
 
   // If this is a trivial constructor, emit a memcpy now before we lose
   // the alignment information on the argument.
@@ -2159,7 +2159,7 @@
     const CXXConstructorDecl *D, bool ForVirtualBase, Address This,
     bool InheritedFromVBase, const CXXInheritedCtorInitExpr *E) {
   CallArgList Args;
-  CallArg ThisArg(RValue::get(This.getPointer()), D->getThisType(getContext()));
+  CallArg ThisArg(RValue::get(This.getPointer()), D->getThisType());
 
   // Forward the parameters.
   if (InheritedFromVBase &&
@@ -2284,7 +2284,7 @@
   CallArgList Args;
 
   // Push the this ptr.
-  Args.add(RValue::get(This.getPointer()), D->getThisType(getContext()));
+  Args.add(RValue::get(This.getPointer()), D->getThisType());
 
   // Push the src ptr.
   QualType QT = *(FPT->param_type_begin());