RFR: JDK-8037414: Licensee Source Bundles build issue

[Erik Joelsson]

Hello,

The file jdk/make/closed/javax/crypto/doc/README.txt is not available to 
licensees. The makefiles currently assumes it's always there as long as 
we build crypto and it's not an OpenJDK build. This change also checks 
that the file is actually in the source too.

Bug: https://bugs.openjdk.java.net/browse/JDK-8037414
Patch inline:
diff -r a94a8944bd2b make/CreateSecurityJars.gmk
--- a/make/CreateSecurityJars.gmk
+++ b/make/CreateSecurityJars.gmk
@@ -284,11 +284,13 @@
    TARGETS += $(LOCAL_POLICY_JAR_LIMITED_UNSIGNED) 
$(LOCAL_POLICY_JAR_UNLIMITED_UNSIGNED)

    ifndef OPENJDK
-    $(JDK_OUTPUTDIR)/jce/unsigned/policy/unlimited/README.txt: \
-        $(JDK_TOPDIR)/make/closed/javax/crypto/doc/README.txt
+    ifneq ($(wildcard 
$(JDK_TOPDIR)/make/closed/javax/crypto/doc/README.txt), )
+      $(JDK_OUTPUTDIR)/jce/unsigned/policy/unlimited/README.txt: \
+          $(JDK_TOPDIR)/make/closed/javax/crypto/doc/README.txt
          $(install-file)

-    TARGETS += $(JDK_OUTPUTDIR)/jce/unsigned/policy/unlimited/README.txt
+      TARGETS += $(JDK_OUTPUTDIR)/jce/unsigned/policy/unlimited/README.txt
+    endif
    endif
  endif

/Erik