Fixes glibc 'make tests' failure running isomac

make[2]: *** [/home3/dank/wk/ixos/dap_interim/linux/3rdParty/crosstool/crosstool-0.15/build/sh4-unknown-linux-gnu/gcc-ss-3_3-20030714-glibc-2.2.5/build-glibc/stdlib/isomac.out] Error 2

isomac.out contains:
...
setjmp.h
#define JB_SIZE (4 * 15)

See http://sources.redhat.com/ml/libc-hacker/2002-11/msg00009.html
and http://www.schweikhardt.net/isomac.c.html

===================================================================
RCS file: /cvs/glibc/libc/sysdeps/sh/bits/setjmp.h,v
retrieving revision 1.4
retrieving revision 1.5
diff -u -r1.4 -r1.5
--- libc/sysdeps/sh/bits/setjmp.h	2001/07/06 04:56:03	1.4
+++ libc/sysdeps/sh/bits/setjmp.h	2002/11/06 00:08:30	1.5
@@ -42,7 +42,9 @@
   } __jmp_buf[1];
 #endif
 
+#if defined __USE_MISC || defined _ASM
 #define JB_SIZE		(4 * 15)
+#endif
 
 /* Test if longjmp to JMPBUF would unwind the frame
    containing a local variable at ADDRESS.  */