Add clang_CXXMethod_isCopyAssignmentOperator to libclang

The new method is a wrapper of `CXXMethodDecl::isCopyAssignmentOperator` and
can be used to recognized copy-assignment operators in libclang.

An export for the method, together with its documentation, was added to
"clang/include/clang-c/Index.h" with an implementation provided in
"clang/tools/libclang/CIndex.cpp". The implementation was based on
similar `clang_CXXMethod.*` implementations, following the same
structure but calling `CXXMethodDecl::isCopyAssignmentOperator` for its
main logic.

The new symbol was further added to "clang/tools/libclang/libclang.map"
to be exported, under the LLVM16 tag.

"clang/tools/c-index-test/c-index-test.c" was modified to print a
specific tag, "(copy-assignment operator)", for cursors that are
recognized by `clang_CXXMethod_isCopyAssignmentOperator`.
A new regression test file,
"clang/test/Index/copy-assignment-operator.cpp", was added to ensure
that the correct constructs were recognized or not by the new function.

The "clang/test/Index/get-cursor.cpp" regression test file was updated
as it was affected by the new "(copy-assignment operator)" tag.

A binding for the new function was added to libclang's python's
bindings, in "clang/bindings/python/clang/cindex.py", adding a new
method for `Cursor`, `is_copy_assignment_operator_method`.

The current release note, `clang/docs/ReleaseNotes.rst`, was modified to
report the new addition under the "libclang" section.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D136604

1 files changed, 2 insertions, 0 deletions

diff --git a/clang/tools/c-index-test/c-index-test.c b/clang/tools/c-index-test/c-index-test.c
index 805f790..108b445 100644
--- a/clang/tools/c-index-test/c-index-test.c
+++ b/clang/tools/c-index-test/c-index-test.c
@@ -910,6 +910,8 @@ static void PrintCursor(CXCursor Cursor, const char *CommentSchemaFile) {
       printf(" (const)");
     if (clang_CXXMethod_isPureVirtual(Cursor))
       printf(" (pure)");
+    if (clang_CXXMethod_isCopyAssignmentOperator(Cursor))
+      printf(" (copy-assignment operator)");
     if (clang_CXXRecord_isAbstract(Cursor))
       printf(" (abstract)");
     if (clang_EnumDecl_isScoped(Cursor))