[Demangle] avoid more std::string_view::substr
In D148959, I removed usage of std::string_view::substr because it may
throw, and libcxxabi cannot use such code. I missed one instance in
llvm::starts_with. That is blocking copying the code back upstream in
D148566.
Mark these helpers noexcept (as they are in C++20) as well, to remind
future travelers.
Make these changes upstream, and copy them back downstream using
libcxxabi/src/demangle/cp-to-llvm.sh.
Reviewed By: #libc_abi, MaskRay, ldionne
Differential Revision: https://reviews.llvm.org/D151260
GitOrigin-RevId: ee740b714ba0de41f48a4fb4717fa9b9a22fedf2
1 file changed
