Correct the detection of hard float arm

* Don't test MACHINE, it's irrelevant to userland and should never be
  used in userland Makefiles.
* If we match armv[67] and CPUTYPE is undefined OR it doesn't have
  'soft' in it, choose armhf.
* Add a note that the soft float on armv[67] may be broken.

Sponsored by: Netflix

lib/libclang_rt/Makefile.inc

@@ -2,12 +2,12 @@
 
 .include <bsd.compiler.mk>
 
-.if ${MACHINE} == "arm"
+# armv[67] is a bit special since we allow a soft-floating version via
+# CPUTYPE matching *soft*. This variant is may not actually work though.
 .if ${MACHINE_ARCH:Marmv[67]*} != "" && \
-    (defined(CPUTYPE) && ${CPUTYPE:M*soft*} == "")
+    (!defined(CPUTYPE) || ${CPUTYPE:M*soft*} == "")
 CRTARCH=	armhf
 .endif
-.endif
 CRTARCH?=	${MACHINE_CPUARCH:C/amd64/x86_64/}
 CRTSRC=		${SRCTOP}/contrib/compiler-rt