Compile Mac OS binaries with unwind tables for libcorkscrew.

Change-Id: I9755d8d39913830180da2ce32bcdd357309ff792
diff --git a/core/combo/HOST_darwin-x86.mk b/core/combo/HOST_darwin-x86.mk
index 63c119e..f2dc7de 100644
--- a/core/combo/HOST_darwin-x86.mk
+++ b/core/combo/HOST_darwin-x86.mk
@@ -50,7 +50,7 @@
 HOST_GLOBAL_LDFLAGS += -isysroot $(sdk_105_root) -mmacosx-version-min=10.5
 endif # build_mac_version is 10.6
 
-HOST_GLOBAL_CFLAGS += -fPIC
+HOST_GLOBAL_CFLAGS += -fPIC -funwind-tables
 HOST_NO_UNDEFINED_LDFLAGS := -Wl,-undefined,error
 
 GCC_REALPATH = $(realpath $(shell which gcc))