Apply -fomit-frame-pointer only to .o/.os files
Since -fomit-frame-pointer is compatible with -pg, apply it only to
.o/.os files.
* sysdeps/unix/sysv/linux/i386/Makefile (CFLAGS-epoll_pwait.c):
Renamed to ...
(CFLAGS-epoll_pwait.o): This.
(CFLAGS-mmap.c): Renamed to ...
(CFLAGS-mmap.o): This.
(CFLAGS-mmap64.c): Renamed to ...
(CFLAGS-mmap64.o): This.
(CFLAGS-epoll_pwait.os): New.
(CFLAGS-mmap.os): Likewise.
(CFLAGS-mmap64.os): Likewise.
(CFLAGS-semtimedop.os): Likewise.
(CFLAGS-semtimedop.c): Renamed to ...
(CFLAGS-semtimedop.o): This.