[Bug middle-end/63279] [5 Regression] Processes hang inside Linux Kernel built with gcc5

["sasha.levin at oracle dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63279

--- Comment #4 from Sasha Levin <sasha.levin at oracle dot com> ---
Here's what I see with 'make V=1' on the kernel:

gcc -Wp,-MD,kernel/.exec_domain.o.d  -nostdinc -isystem
/home/sasha/gcc-inst/lib/gcc/x86_64-unknown-linux-gnu/4.10.0/include
-I./arch/x86/include -Iarch/x86/include/generated  -Iinclude
-I./arch/x86/include/uapi -Iarch/x86/include/generated/uapi -I./include/uapi
-Iinclude/generated/uapi -include ./include/linux/kconfig.h -D__KERNEL__ -Wall
-Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common
-Werror-implicit-function-declaration -Wno-format-security -m64 -mno-mmx
-mno-sse -mno-80387 -mno-fp-ret-in-387 -mpreferred-stack-boundary=3
-march=native -mno-red-zone -mcmodel=kernel -funit-at-a-time
-maccumulate-outgoing-args -DCONFIG_X86_X32_ABI -DCONFIG_AS_CFI=1
-DCONFIG_AS_CFI_SIGNAL_FRAME=1 -DCONFIG_AS_CFI_SECTIONS=1 -DCONFIG_AS_FXSAVEQ=1
-DCONFIG_AS_CRC32=1 -DCONFIG_AS_AVX=1 -DCONFIG_AS_AVX2=1 -pipe
-Wno-sign-compare -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -mno-sse2
-mno-3dnow -mno-avx -fno-delete-null-pointer-checks -O2
--param=allow-store-data-races=0 -fno-reorder-blocks -fno-ipa-cp-clone
-fno-partial-inlining -Wframe-larger-than=2048 -fstack-protector
-Wno-unused-but-set-variable -fno-omit-frame-pointer
-fno-optimize-sibling-calls -fno-var-tracking-assignments -g -gdwarf-4 -pg
-mfentry -DCC_USING_FENTRY -fno-inline-functions-called-once
-Wdeclaration-after-statement -Wno-pointer-sign -fno-strict-overflow
-fconserve-stack -Werror=implicit-int -Werror=strict-prototypes
-Werror=date-time -DCC_HAVE_ASM_GOTO    -D"KBUILD_STR(s)=#s"
-D"KBUILD_BASENAME=KBUILD_STR(exec_domain)" 
-D"KBUILD_MODNAME=KBUILD_STR(exec_domain)" -c -o kernel/.tmp_exec_domain.o
kernel/exec_domain.c