Fixed forcing FAST LOCKS for arm6.

Use FAST locking support for arm6 too.
For Linux, use POSIX as default locking support.

(cherry picked from commit 058e16f)

Makefile.defs

@@ -832,6 +832,10 @@ ifeq ($(ARCH), arm)
 	use_fast_lock=yes
 endif
 
+ifeq ($(ARCH), arm6)
+	use_fast_lock=yes
+endif
+
 ifeq ($(ARCH), ppc)
 	use_fast_lock=yes
 endif
@@ -1459,7 +1463,7 @@ ifeq ($(OS), linux)
 			-DHAVE_MSG_NOSIGNAL -DHAVE_MSGHDR_MSG_CONTROL -DHAVE_ALLOCA_H \
 			-DHAVE_TIMEGM
 	ifneq ($(found_lock_method), yes)
-		DEFS+= -DUSE_SYSV_SEM  # try posix sems
+		DEFS+= -DUSE_POSIX_SEM  # try posix sems
 		found_lock_method=yes
 	endif
 	# check for >= 2.5.44