asan: disable odd_stack_size test for powerpc

Fail on powerpc64 bots with:
AddressSanitizer: CHECK failed: asan_thread.cpp:315 "((AddrIsInStack((uptr)&local))) != (0)"
https://lab.llvm.org/buildbot/#/builders/18/builds/8162
Disable to unbreak bots.

Differential Revision: https://reviews.llvm.org/D145902