[python bindings] Fix Cursor.result_type for ObjC method declarations - Bug 36677
In cindex.py, Cursor.result_type called into the wrong libclang
function, causing cursors for ObjC method declarations to return invalid
result types. Fixes Bug 36677.
Reviewers: jbcoe, rsmith
Reviewed By: jbcoe
Subscribers: cfe-commits, llvm-commits
Differential Revision: https://reviews.llvm.org/D45671
Patch by kjteske (Kyle Teske).