Use Mac OS X SDK 10.6.

Change-Id: Ie36914ab1763c5606111f7501c97ed97517e7187
diff --git a/core/combo/HOST_darwin-x86.mk b/core/combo/HOST_darwin-x86.mk
index f2dc7de..c84e375 100644
--- a/core/combo/HOST_darwin-x86.mk
+++ b/core/combo/HOST_darwin-x86.mk
@@ -34,21 +34,17 @@
 HOST_GLOBAL_LDFLAGS += -static
 endif # BUILD_HOST_static
 
-# Use the Mac OSX SDK 10.5 if the build host is 10.6
-build_mac_version := $(shell sw_vers -productVersion)
-ifneq ($(filter 10.6.%, $(build_mac_version)),)
-sdk_105_root := /Developer/SDKs/MacOSX10.5.sdk
-ifeq ($(wildcard $(sdk_105_root)),)
+mac_sdk_version := 10.6
+mac_sdk_root := /Developer/SDKs/MacOSX$(mac_sdk_version).sdk
+ifeq ($(wildcard $(mac_sdk_root)),)
 $(warning *****************************************************)
-$(warning * You are building on Mac OSX 10.6.)
-$(warning * Can not find SDK 10.5 at $(sdk_105_root))
+$(warning * Can not find SDK $(mac_sdk_version) at $(mac_sdk_root))
 $(warning *****************************************************)
 $(error Stop.)
 endif
 
-HOST_GLOBAL_CFLAGS += -isysroot $(sdk_105_root) -mmacosx-version-min=10.5
-HOST_GLOBAL_LDFLAGS += -isysroot $(sdk_105_root) -mmacosx-version-min=10.5
-endif # build_mac_version is 10.6
+HOST_GLOBAL_CFLAGS += -isysroot $(mac_sdk_root) -mmacosx-version-min=$(mac_sdk_version)
+HOST_GLOBAL_LDFLAGS += -isysroot $(mac_sdk_root) -mmacosx-version-min=$(mac_sdk_version)
 
 HOST_GLOBAL_CFLAGS += -fPIC -funwind-tables
 HOST_NO_UNDEFINED_LDFLAGS := -Wl,-undefined,error