Fix `-Wgnu-zero-variadic-macro-arguments` in GMock
Passing zero arguments to the variadic part of a macro is a GNU
extension and triggers warnings when build projects using GMock with
`-pedantic`.
- Fix uses of `GMOCK_PP_INTERNAL_16TH` to always receive at least 17
arguments. (this was triggered when `GMOCK_PP_NARG` or `GMOCK_PP_HAS_COMMA`
were used with an argument containing no commas).
- Fix `GMOCK_PP_HEAD` to append a dummy unused argument so that
`GMOCK_PP_INTERNAL_HEAD` always has two arguments.
PiperOrigin-RevId: 310414611
This is part (hopefully all) of the fixes for #776. The top-level
configure.ac configures googletest first and then googlemock.
With this changes it is possible to embed googletest into another
project that uses autoconf. For an example (though it is WIP), see
the commits (and soon PR) referenced from google/protobuf#236.
Abseil Team
Carlo Wood
Chris
Tengfei Niu
wxf
Syohei YOSHIDA
Carlos O'Ryan
Arkadiy Shapkin
misterg
Claus Stovgaard
Don Huff
Jacob Meacham