[test] Add test for demangling GNU ABI tags

[RAOF]

I couldn't find test cases for the demangler, but https://reviews.llvm.org/D44615 is the LLD test case that this fixes.

[• espindola]

Changes to the demangler should go first to libcxxabi/src/cxa_demangle.cpp.

[RAOF]

Looks like libcxxabi/src/cxx_demangle.cpp already supports this:

2914: Node *Db::parseAbiTags(Node *N) {

and the associated AbiTagAttr class.

[• espindola]

In D44614#1042866, @RAOF wrote:

Looks like libcxxabi/src/cxx_demangle.cpp already supports this:

2914: Node *Db::parseAbiTags(Node *N) {

and the associated AbiTagAttr class.

So this was fixed by r327859?

[RAOF]

Added a llvm-cxxfilt test for the demanger changes.

[RAOF]

Yes! What timing. This was indeed fixed in r327859.

I've replaced the patch with a testcase verifying that it's fixed instead.

[• espindola]

LGTM.
Do you have commit access?

[RAOF]

I do not have commit access; could you please commit it?

[• espindola]

r328256

test/tools/llvm-cxxfilt/abitag.test

+RUN: llvm-cxxfilt _Z14returns_stringB5cxx11v _Z6globalB5cxx11 _Z6globalB12a_longer_tag | FileCheck %s
+
+CHECK: returns_string[abi:cxx11]()
+CHECK-NEXT: global[abi:cxx11]
+CHECK-NEXT: global[abi:a_longer_tag]
+