Optimize for size on pc98. It enables to boot a kernel again.

I don't know what's wrong (loader, boot2 or others), but this change is
effective.

Tested by:	NAKAJI Hiroyuki
MFC after:	3 days

lib/libstand/Makefile

@@ -22,6 +22,9 @@ CFLAGS+=	-mno-mmx -mno-3dnow -mno-sse -mno-sse2
 .if ${MACHINE_ARCH} == "i386"
 CFLAGS+=	-mno-sse3
 .endif
+.if ${MACHINE} == "pc98"
+CFLAGS+=	-Os
+.endif
 .if ${MACHINE_ARCH} == "powerpc"
 CFLAGS+=	-msoft-float -D_STANDALONE
 .endif

sys/boot/ficl/Makefile

@@ -18,7 +18,7 @@ CFLAGS+=	-mno-sse3
 CFLAGS+=	-msoft-float
 .endif
 .if ${MACHINE} == "pc98"
-CFLAGS+=	-DPC98
+CFLAGS+=	-Os -DPC98
 .endif
 .if HAVE_PNP
 CFLAGS+=	-DHAVE_PNP

sys/boot/pc98/Makefile.inc

@@ -6,7 +6,8 @@ BINDIR?=	/boot
 
 LOADER_ADDRESS?=0x100000
 CFLAGS+=	-ffreestanding -mpreferred-stack-boundary=2 \
-		-mno-mmx -mno-3dnow -mno-sse -mno-sse2 -mno-sse3
+		-mno-mmx -mno-3dnow -mno-sse -mno-sse2 -mno-sse3 \
+		-Os
 LDFLAGS+=	-nostdlib
 
 # BTX components