Simplify depending on static sanitizer runtimes

The dependencies on static runtimes are getting compilicated, as they
vary on whether or not they should hide or export symbols from the
runtime.  Instead of setting flags to try to add the right static
runtime later, add them as dependencies immediately with a call to
addStaticDeps.

Test: sanitize_test.go
Change-Id: I5fb3ee29b31ce99d8feac262fcf71d19396dc68d