Redo r325502

:U:Mfoo expands to :Mfoo, apparently. Explicit check for CPUTYPE being
defined, and test for it's value not containing *soft* before calling CRTARCH
armhf.

Tested, somewhat. Unfortunately recent changes appear to have affected
cross-builds where it no longer works, per my tests after universe12a being
upgraded from 07/2017 to 11/2017 sources (DESTDIR isn't being used in WORLDTMP;
MK_SYSTEM_COMPILER might be causing issues right now).

MFC after:	1 week
MFC with:	r325502
Reported by:	imp

lib/libclang_rt/Makefile.inc

@@ -3,7 +3,8 @@
 .include <bsd.compiler.mk>
 
 .if ${MACHINE} == "arm"
-.if ${MACHINE_ARCH:Marmv[67]*} != "" && ${CPUTYPE:U:M*soft*} == ""
+.if ${MACHINE_ARCH:Marmv[67]*} != "" && \
+    (defined(CPUTYPE) && ${CPUTYPE:M*soft*} == "")
 CRTARCH=	armhf
 .endif
 .endif