- don't force compiler flags
- don't unconditionally set -ftrampolines, it is gcc-only.

Index: Makefile
--- Makefile.orig
+++ Makefile
@@ -144,7 +144,7 @@ ASTTOPDIR:=$(subst $(space),\$(space),$(CURDIR))
 OVERWRITE=y
 
 # Include debug and macro symbols in the executables (-g) and profiling info (-pg)
-DEBUG=-g3
+#DEBUG=-g3
 
 # Asterisk.conf is located in ASTETCDIR or by using the -C flag
 # when starting Asterisk
@@ -237,7 +237,7 @@ ifeq ($(OSARCH),NetBSD)
 endif
 
 ifeq ($(OSARCH),OpenBSD)
-  _ASTCFLAGS+=-pthread -ftrampolines
+  _ASTCFLAGS+=-pthread
 endif
 
 ifeq ($(OSARCH),linux-uclibc)
