Pass -fno-sanitize=vptr,function for musl

The prebuilts for musl have the necessary symbols for vptr and function
sanitizers, but enabling them implicitly enables RTTI which causes RTTI
mismatch issues with dependencies.

Bug: 215802826
Test: m USE_HOST_MUSL=true host-native
Change-Id: I93edfd617d99efcac0eca58bb3f3c173c4fa121a