[Bug bootstrap/117893] [15 regression] space before -O0 in CFLAGS incorrectly removed

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117893

--- Comment #6 from Sam James <sjames at gcc dot gnu.org> ---
./configure BOOT_C{,XX}FLAGS="-O3" STAGE1_C{,XX}FLAGS="-O3"