This is a more aggressively "modern" approach than my first few attempts.
Apparently we can't just follow the Rule of Zero for the `Ne` matcher in
particular, because if we do, one of the unit tests hits
"recursive template instantiation exceeded maximum depth of 256"
on Clang.
Fixes#1305.
Get rid of gmock-generated-matchers.h and gmock-generated-matchers.h.pump.
Stop using pump for MATCHER* macroses generation.
PiperOrigin-RevId: 293878808
This merges a Google-internal change (117235625).
Original CL description:
This CL was created manually in about an hour with sed, a Python script
to find all the places unqualified 'string' was mentioned, and some help
from Emacs to add the "std::" qualifications, plus a few manual tweaks.
