[BUILD] only enable regparm on x86 to avoid useless warnings
It complains at least on Solaris/sparc64 and OpenBSD/vax.
diff --git a/Makefile b/Makefile
index 03e7917..d19ce34 100644
--- a/Makefile
+++ b/Makefile
@@ -57,8 +57,8 @@
# CPU dependant optimizations
COPTS.generic = -O2
-COPTS.i586 = -O2 -march=i586
-COPTS.i686 = -O2 -march=i686
+COPTS.i586 = -O2 -march=i586 -DCONFIG_HAP_USE_REGPARM
+COPTS.i686 = -O2 -march=i686 -DCONFIG_HAP_USE_REGPARM
COPTS.ultrasparc = -O6 -mcpu=v9 -mtune=ultrasparc
# options for standard regex library