x86: Mark OPTIMIZE_INLINING broken

So Ingo finally did figure out why UML broke with this option: UML
passes gcc the -fno-unit-at-a-time flag, and apparently that wreaks
havoc with gcc's inlining.

We could turn off -fno-unit-at-a-time for UML for gcc4+ (which is what
x86 does), but there's bad blood about this whole option, and it does
show that the thing is just fragile as heck.

So let tempers cool, and disable the thing, and we can revisit the
decision later.

Cc: Adrian Bunk <bunk@kernel.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/x86/Kconfig.debug

@@ -257,6 +257,7 @@ config CPA_DEBUG
 
 config OPTIMIZE_INLINING
 	bool "Allow gcc to uninline functions marked 'inline'"
+	depends on BROKEN
 	help
 	  This option determines if the kernel forces gcc to inline the functions
 	  developers have marked 'inline'. Doing so takes away freedom from gcc to