[demangler] Don't allow the template parameters from the <encoding> in a
<local-name> to leak out into later parts of the name.

This caused us to fail to demangle certain constructs involving generic
lambdas.

Cr-Mirrored-From: https://chromium.googlesource.com/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 553dbb6d7b32cc786281dea2c58a420bcbc9bb82
2 files changed