Resolve compile error under FreeBSD

We now set _ASTCFLAGS+=-march=i686 for i386 processors, still allowing ASTCFLAGS
to override the setting.

Review: https://reviewboard.asterisk.org/r/1043/


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@297404 65c4cc65-6c06-0410-ace0-fbb531ad65f3

Makefile

@@ -235,6 +235,9 @@ ifeq ($(PROC),ppc)
 endif
 
 ifeq ($(OSARCH),FreeBSD)
+  ifeq ($(PROC),i386)
+    _ASTCFLAGS+=-march=i686
+  endif
   # -V is understood by BSD Make, not by GNU make.
   BSDVERSION=$(shell make -V OSVERSION -f /usr/share/mk/bsd.port.subdir.mk)
   _ASTCFLAGS+=$(shell if test $(BSDVERSION) -lt 500016 ; then echo "-D_THREAD_SAFE"; fi)