googletest

Googletest export

Revision of recent DoubleNearPredFormat change to support more toolchains.

isnan() is a macro in C99, and std::isnan() is a function in C++11.  The previous change used `isnan` directly, and broke some tests in open source.

This CL changes it to follow the practice in gmock-matchers.h, and spell uses of isnan as
  (std::isnan)(f)
.  The parens around `std::isnan` prevent it from being recognized as a macro in the preprocessor.

PiperOrigin-RevId: 333374377