ext: upgrade to googletest 1.12.0

Upgrade googletest to 1.12.0
upstream commit: 15460959cbbfa20e66ef0b5ab497367e47fc0a04

sha1sum e1e4ab7f4add6d403c37970a83a596b3081077d6 generated by command:
find . -type f ! -name SConscript ! -path "./.*" -print0 \
| sort -z | xargs -0 sha1sum | sha1sum

This upgrade is mainly for solving the infinite-recursion warning from
g++12

ext/googletest/googlemock/include/gmock/internal/gmock-internal-utils.h: In function ‘testing::internal::Invalid<gem5::Port&>()gem5::Port&’:
ext/googletest/googlemock/include/gmock/internal/gmock-internal-utils.h:296:10: error: infinite recursion detected [-Werror=infinite-recursion]
  296 | inline T Invalid() {
      |          ^~~~~~~
ext/googletest/googlemock/include/gmock/internal/gmock-internal-utils.h:301:20: note: recursive call
  301 |   return Invalid<T>();
      |          ~~~~~~~~~~^~
ext/googletest/googlemock/include/gmock/internal/gmock-internal-utils.h: In function ‘testing::internal::Invalid<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&>()std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&’:
ext/googletest/googlemock/include/gmock/internal/gmock-internal-utils.h:296:10: error: infinite recursion detected [-Werror=infinite-recursion]
  296 | inline T Invalid() {
      |          ^~~~~~~
ext/googletest/googlemock/include/gmock/internal/gmock-internal-utils.h:301:20: note: recursive call
  301 |   return Invalid<T>();
      |          ~~~~~~~~~~^~

Change-Id: I14594f7bc148281784043b3f715173316e6d62d4
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/65211
Maintainer: Gabe Black <gabeblack@google.com>
Reviewed-by: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
221 files changed