Add -Wl,-pie linker option for macOS and use it instead of -pie

configure.ac

@@ -495,7 +495,11 @@ if test x$use_hardening != xno; then
   if test x$TARGET_OS != xwindows; then
     # All windows code is PIC, forcing it on just adds useless compile warnings
     AX_CHECK_COMPILE_FLAG([-fPIE],[PIE_FLAGS="-fPIE"],[AC_MSG_ERROR(Cannot enable -fPIE)])
-    AX_CHECK_LINK_FLAG([[-pie]], [HARDENED_LDFLAGS="$HARDENED_LDFLAGS -pie"],[AC_MSG_ERROR(Cannot enable -pie)])
+    if test x$BUILD_OS = xdarwin; then
+      AX_CHECK_LINK_FLAG([[-Wl,-pie]], [HARDENED_LDFLAGS="$HARDENED_LDFLAGS -Wl,-pie"],[AC_MSG_ERROR(Cannot enable -Wl,-pie)])
+    else
+      AX_CHECK_LINK_FLAG([[-pie]], [HARDENED_LDFLAGS="$HARDENED_LDFLAGS -pie"],[AC_MSG_ERROR(Cannot enable -pie)])
+    fi
   else
     # These are only available on Windows.
     AX_CHECK_LINK_FLAG([[-Wl,--dynamicbase]], [HARDENED_LDFLAGS="$HARDENED_LDFLAGS -Wl,--dynamicbase"],[AC_MSG_ERROR(Cannot enable --dynamicbase)])