We must make the access of 'push_back' dependent, too. Otherwise, name
lookup does not find the name. Earlier compilers were more permissive and
did find the name.
(cherry picked from upstream commit 5f55847d441aba7742417e78c3b4fbe8344acc5e)
When a string ends in an incomplete multi-byte sequence, gdb adds an
<incomplete sequence...> fragment to the end of the string. Previously,
this resulted in a parse error and incomplete variable information.
Reported by Kevin Lemay.
(cherry picked from upstream commit 03da8a5ec97c8c7b125b2bd453d2f1c3a018d477)