Previously, code defaulted to using libstdc++ (which was GNU libstdc++
on the host, or Bionic's "libstdc++" on the target). Now we default to
libc++. The exception for this is when using mingw, because we cannot
build libc++ for mingw.
Change-Id: I68726fa26cdcb6263f17c838d3e859debd57fae1
Windows does not have pthread support, and by defining the
GTEST_OS_WINDOWS flag, pthread support will not be built into
the windows version of gtest.
Change-Id: I0571fc52e77bb04175470d5750a7e2f46cdd5e86
Target tests weren't approrpiately using the libc++ gtest for
libc++_static, and the hosts tests were still using the old check.
Change-Id: I13813d5f09673b144b2dfead93eb81cb4bae0e34
