RFR: JDK-8147930: Langtools test Makefile still requires special make in Cygwin

[Erik Joelsson]

The langtools test Makefile doesn't work in Cygwin with the default 
make. It still expects the specially built gnu make which handles ':' in 
path names and particularly in rule declarations.

The cause of the failure is JCK_HOME, which on Windows defaults to a 
string starting with "J:/".

Bug: https://bugs.openjdk.java.net/browse/JDK-8147930
Patch:
diff -r 1fd828240c4d test/Makefile
--- a/test/Makefile
+++ b/test/Makefile
@@ -412,7 +412,15 @@
      fi

  # Check to make sure these directories exist
-check-jck: $(JCK_HOME) $(PRODUCT_HOME)
+check-jck:
+    if [ ! -d '$(JCK_HOME)' ]; then \
+        echo "JCK_HOME $(JCK_HOME) missing" ; \
+        $(EXIT) 1 ; \
+    fi
+    if [ ! -d '$(PRODUCT_HOME)' ]; then \
+        echo "PRODUCT_HOME $(PRODUCT_HOME) missing" ; \
+        $(EXIT) 1 ; \
+    fi

  all-summary: FRC
      @if [ -n "`find $(TEST_OUTPUT_DIR) -name status.txt`" ]; then


/Erik