implement polite waiting (#685)

* implement polite waiting

* Update src/snmalloc/pal/pal_linux.h

Co-authored-by: Matthew Parkinson <mjp41@users.noreply.github.com>

* fix build issues

* fix more build issues

* support _umtx_op for freebsd

* unify waiting style

* fix

* address CR

Co-authored-by: Matthew Parkinson <mjp41@users.noreply.github.com>

* support macos

* static dispatch os APIs for apple

* make wait_on_address configurable via cmake

* undo extra include

* fix macos build

* fix clang-tidy build

---------

Co-authored-by: Matthew Parkinson <mjp41@users.noreply.github.com>

.github/workflows/main.yml

@@ -479,7 +479,7 @@ jobs:
         git diff --exit-code
     - name: Run clang-tidy
       run: |
-        clang-tidy-15  src/snmalloc/override/malloc.cc  -header-filter="`pwd`/*" -warnings-as-errors='*' -export-fixes=tidy.fail -- -std=c++17 -mcx16 -DSNMALLOC_PLATFORM_HAS_GETENTROPY=0 -Isrc
+        clang-tidy-15  src/snmalloc/override/malloc.cc  -header-filter="`pwd`/*" -warnings-as-errors='*' -export-fixes=tidy.fail -- -std=c++17 -mcx16 -DSNMALLOC_USE_WAIT_ON_ADDRESS=1 -DSNMALLOC_PLATFORM_HAS_GETENTROPY=0 -Isrc
         if [ -f tidy.fail ] ; then
           cat tidy.fail
           exit 1