[ci] Checkout a specific Google Test commit (#1931)

diff --git a/.appveyor.yml b/.appveyor.yml
index a50c7c2..567eb20 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -46,7 +46,8 @@
 
 before_build:
   - git clone --depth=1 https://github.com/KhronosGroup/SPIRV-Headers.git external/spirv-headers
-  - git clone --depth=1 https://github.com/google/googletest.git external/googletest
+  - git clone https://github.com/google/googletest.git external/googletest
+  - cd external && cd googletest && git reset --hard 0fc5466dbb9e623029b1ada539717d10bd45e99e && cd .. && cd ..
   - git clone --depth=1 https://github.com/google/effcee.git external/effcee
   - git clone --depth=1 https://github.com/google/re2.git external/re2
   # Set path and environment variables for the current Visual Studio version
diff --git a/kokoro/android/build.sh b/kokoro/android/build.sh
index e31744f..4e407f3 100644
--- a/kokoro/android/build.sh
+++ b/kokoro/android/build.sh
@@ -35,7 +35,8 @@
 
 cd $SRC
 git clone --depth=1 https://github.com/KhronosGroup/SPIRV-Headers external/spirv-headers
-git clone --depth=1 https://github.com/google/googletest          external/googletest
+git clone https://github.com/google/googletest          external/googletest
+cd external && cd googletest && git reset --hard 0fc5466dbb9e623029b1ada539717d10bd45e99e && cd .. && cd ..
 git clone --depth=1 https://github.com/google/effcee              external/effcee
 git clone --depth=1 https://github.com/google/re2                 external/re2
 
diff --git a/kokoro/check-format/build.sh b/kokoro/check-format/build.sh
index 2a8d50f..ca5687e 100644
--- a/kokoro/check-format/build.sh
+++ b/kokoro/check-format/build.sh
@@ -31,7 +31,8 @@
 
 cd $SRC
 git clone --depth=1 https://github.com/KhronosGroup/SPIRV-Headers external/spirv-headers
-git clone --depth=1 https://github.com/google/googletest          external/googletest
+git clone https://github.com/google/googletest          external/googletest
+cd external && cd googletest && git reset --hard 0fc5466dbb9e623029b1ada539717d10bd45e99e && cd .. && cd ..
 git clone --depth=1 https://github.com/google/effcee              external/effcee
 git clone --depth=1 https://github.com/google/re2                 external/re2
 curl -L http://llvm.org/svn/llvm-project/cfe/trunk/tools/clang-format/clang-format-diff.py -o utils/clang-format-diff.py;
diff --git a/kokoro/ndk-build/build.sh b/kokoro/ndk-build/build.sh
index d51f071..6b648e7 100644
--- a/kokoro/ndk-build/build.sh
+++ b/kokoro/ndk-build/build.sh
@@ -34,7 +34,8 @@
 # Get the dependencies.
 cd $SRC
 git clone --depth=1 https://github.com/KhronosGroup/SPIRV-Headers external/spirv-headers
-git clone --depth=1 https://github.com/google/googletest          external/googletest
+git clone https://github.com/google/googletest          external/googletest
+cd external && cd googletest && git reset --hard 0fc5466dbb9e623029b1ada539717d10bd45e99e && cd .. && cd ..
 git clone --depth=1 https://github.com/google/effcee              external/effcee
 git clone --depth=1 https://github.com/google/re2                 external/re2
 
diff --git a/kokoro/scripts/linux/build.sh b/kokoro/scripts/linux/build.sh
index 599a43f..6442978 100644
--- a/kokoro/scripts/linux/build.sh
+++ b/kokoro/scripts/linux/build.sh
@@ -73,7 +73,8 @@
 
 cd $SRC
 git clone --depth=1 https://github.com/KhronosGroup/SPIRV-Headers external/spirv-headers
-git clone --depth=1 https://github.com/google/googletest          external/googletest
+git clone https://github.com/google/googletest          external/googletest
+cd external && cd googletest && git reset --hard 0fc5466dbb9e623029b1ada539717d10bd45e99e && cd .. && cd ..
 git clone --depth=1 https://github.com/google/effcee              external/effcee
 git clone --depth=1 https://github.com/google/re2                 external/re2
 
diff --git a/kokoro/scripts/macos/build.sh b/kokoro/scripts/macos/build.sh
index a7f0453..3f72520 100644
--- a/kokoro/scripts/macos/build.sh
+++ b/kokoro/scripts/macos/build.sh
@@ -32,7 +32,8 @@
 
 cd $SRC
 git clone --depth=1 https://github.com/KhronosGroup/SPIRV-Headers external/spirv-headers
-git clone --depth=1 https://github.com/google/googletest          external/googletest
+git clone https://github.com/google/googletest          external/googletest
+cd external && cd googletest && git reset --hard 0fc5466dbb9e623029b1ada539717d10bd45e99e && cd .. && cd ..
 git clone --depth=1 https://github.com/google/effcee              external/effcee
 git clone --depth=1 https://github.com/google/re2                 external/re2
 
diff --git a/kokoro/scripts/windows/build.bat b/kokoro/scripts/windows/build.bat
index a2472fb..0e0c7a1 100644
--- a/kokoro/scripts/windows/build.bat
+++ b/kokoro/scripts/windows/build.bat
@@ -26,7 +26,8 @@
 
 cd %SRC%
 git clone --depth=1 https://github.com/KhronosGroup/SPIRV-Headers external/spirv-headers
-git clone --depth=1 https://github.com/google/googletest          external/googletest
+git clone https://github.com/google/googletest          external/googletest
+cd external && cd googletest && git reset --hard 0fc5466dbb9e623029b1ada539717d10bd45e99e && cd .. && cd ..
 git clone --depth=1 https://github.com/google/effcee              external/effcee
 git clone --depth=1 https://github.com/google/re2                 external/re2