Pull gcc "asm goto" miscompilation workaround from Ingo Molnar:
"This is the fix for the GCC miscompilation discussed in the following
lkml thread:
[x86] BUG: unable to handle kernel paging request at 00740060
The bug in GCC has been fixed by Jakub and the fix will be part of the
GCC 4.8.2 release expected to be released next week - so the quirk's
version test checks for <= 4.8.1.
The quirk is only added to compiler-gcc4.h and not to the higher level
compiler.h because all asm goto uses are behind a feature check"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
compiler/gcc4: Add quirk for 'asm goto' miscompilation bug
c786e90bb2