Revert "ART: Compiler support for invoke-polymorphic."

This reverts commit 02e3092f.

Reasons for revert:

- Breaks MIPS/MIPS64 build.
- Fails under GCStress test on x64.
- Different x64 build configuration doesn't like relocation.

Change-Id: I512555b38165d05f8a07e8aed528f00302061001