Update googletest to 1.18.0 and SIMDe to 0.8.2.

Googletest 1.18 asks for CMake 3.13 or newer, so configuring the tests no longer warns that CMake compatibility below 3.10 is deprecated.

Co-authored-by: Cursor <cursoragent@cursor.com>

thirdparty/simde/CONTRIBUTING.md

@@ -57,6 +57,26 @@ platform.  Here are a few to try:
 If you need a flag not listed above, please let us know so we can add
 it to the list.
 
+#### Single test
+
+Compile and run a specific test. Switch `emul` for `native`, and `/c` for `/cpp`
+as needed.
+
+```
+meson test --print-errorlogs arm/neon/qabs/emul/c
+```
+
+Using `meson test` instead of `ninja` and directly executing the test
+is helpful for emscripten and other architectures where are there extra steps needed
+(changing the directory, using `v8` to run`, etc..).
+
+Just compile one specific test with verbose output. Useful for debugging
+compiler errors.
+
+```
+meson compile --verbose test/arm/neon/qabs-emul-c
+```
+
 ### On Windows:
 ```bash
 "C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Auxiliary\Build\vcvars64.bat" arm64