Clean up OatQuickMethodHeader after Quick removal.

This reduces the size of the pre-header by 8 bytes, reducing
oat file size and mmapped .text section size. The memory
needed to store a CompiledMethod by dex2oat is also reduced,
for 32-bit dex2oat by 8B and for 64-bit dex2oat by 16B. The
aosp_flounder-userdebug 32-bit and 64-bit boot.oat are each
about 1.1MiB smaller.

Disable the broken StubTest.IMT, b/27991555 .

Change-Id: I05fe45c28c8ffb7a0fa8b1117b969786748b1039
38 files changed