Remove compile/link variables and hard-wired macOS SDK version

* Not sure these are needed anymore
* Having them lead to double-include issues I couldn't resolve
* Works just fine without it
* Newer SDKs should be fine as long as we keep the desired deployment target

build.sh

@@ -816,18 +816,8 @@ case $TARGET in
         build_linux || failure
         ;;
     $TARGET_MAC)
-        if [ -d /Users/Shared/Developer/SDKs/MacOSX10.8.sdk ]; then
-            echo "Preparing Mac OS X 10.8 SDK build environment..." | tee -a $LOGFILE
-            export LDFLAGS="-isysroot /Users/Shared/Developer/SDKs/MacOSX10.8.sdk -Wl,-syslibroot,/Users/Shared/Developer/SDKs/MacOSX10.8.sdk -arch x86_64 $LDFLAGS"
-            export CPPFLAGS="-isysroot /Users/Shared/Developer/SDKs/MacOSX10.8.sdk -arch x86_64 $CPPFLAGS"
-            export CFLAGS="-isysroot /Users/Shared/Developer/SDKs/MacOSX10.8.sdk -arch x86_64 $CFLAGS"
-            export CXXFLAGS="-isysroot /Users/Shared/Developer/SDKs/MacOSX10.8.sdk -arch x86_64 $CXXFLAGS"
-            export SDKROOT="/Users/Shared/Developer/SDKs/MacOSX10.8.sdk"
+        echo "Setting macOS 10.8 deployment target..." | tee -a $LOGFILE
         export MACOSX_DEPLOYMENT_TARGET=10.8
-        else
-            echo "Mac OS X 10.8 SDK required but missing (in /Users/Shared/Developer/SDKs)!" | tee -a $LOGFILE
-            failure
-        fi
         check_prerequisites || failure
         prepare_tree || failure
         build_mac $TARGET_MAC || failure