Making sure we only use ASAN with debug builds, and switching most of CI to run tests with that profile. Valgrind is left using release builds because ASAN + Valgrind conflict without more care.
Enabling ASAN for GCC in addition to Clang. GCC has also had ASAN support built-in for a long time. We might as well use it for more builds.
Adding simple checks in CI that debug builds are using ASAN and release builds aren't. Presently this isn't comprehensive, but a quick safety check on Linux hosts using nm.
This branch resolves https://github.com/rustls/rustls-ffi/issues/423 by:
nm.