The script to run cppcheck failed for most files in source/ because
of a syntax error in MEM_guardedalloc.h with attribute functions.
Workaround the error by including BLI_compiler_attrs.h directly.
Other changes:
- Specify c++17 / c11 standards for C++ & C.
- Resolve errors from undefined integer ranges.
- Set the check level to exhaustive so checks always run.
- Suppress noisy missingIncludeSystem warning.
- Move run-time compiler defines into a temporary include
which resolves argument quoting errors when cppcheck is used with
clang's parser.
cbee0f5477