Building gcc 4.9.0 on sparc fails. The patch from https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59758#c10 works for me. Please include in the patchset.
*** This bug has been marked as a duplicate of bug 504200 ***
hmm, or not. sparc has ASAN support, just need to fix it.
this is included in gcc-4.9.2, so let's just roll with that rather than backport