Make build work on macos

Change-Id: Idfdbb4d72f5f346cf5147e67792492a5a753653a
Reviewed-on: https://fuchsia-review.googlesource.com/c/intellij-language-fidl/+/628502
Reviewed-by: Alex Zaslavsky <azaslavsky@google.com>

BUILD

diff --git a/BUILD b/BUILD
index 323cb4a..4f03ced 100644
--- a/BUILD
+++ b/BUILD
@@ -31,7 +31,7 @@
     ],
     cmd =
         """ absolutify() { [[ "$$1" =~ ^/ ]] && echo "$$1" || echo "$$PWD/$$1"; };
-            TMP=`absolutify $$(mktemp -d -p .)`;
+            TMP=`absolutify $$(mktemp -d $${PWD}/tmp.XXXXXXXX)`;
             JAR=`absolutify $(JAVABASE)`/bin/jar;
             OUT=`absolutify $(@D)`;
             PLUGIN=`absolutify $(location :fidlplugin_jar_deploy.jar)`;