Fix correctness for fast path class loading

For the fast path, we currently remove all exceptions and only return
ClassNotFoundExceptions. This CL preserves exceptions that might occur
such as linkage errors.

The follow up is to add an additional fast path for faster class not
found exception generation.

Bug: 130310316
Bug: 130293184
Bug: 130209120
Test: test-art-host

(cherry picked from commit ca19f9a8547999cb13de06458364d64ab143cb09)

Merged-In: Iae55aaaae2be5b1330e8e54bee36e862cf9e12e0
Change-Id: I2b858a1869c0c9b6564d8722f0cf662379c237d4