When --iree-llvmcpu-sanitize=address is enabled, we should auto set --iree-llvmcpu-link-embedded=false

The test suite futzes with this at the CMake level but that still leaves the footgun in the compiler. Specifying the first flag causes an opaque link error about missing ASAN symbols with no clue as to how to fix it.

Recommend just making this work correctly when --iree-llvmcpu-sanitize=address is specified. Then also remove the checks and manual massaging done at the CMake level for the test suite to manage the --iree-llvmcpu-link-embedded flag.