8004803: build-infra: Cannot use icedtea as boot for closed build.

Summary: Set bootclasspath to javac and not the running jvm
Reviewed-by: ohair

makefiles/CreateJars.gmk

@@ -810,9 +810,8 @@ EXPORTED_PRIVATE_PKGS = com.sun.servicetag \
 $(IMAGES_OUTPUTDIR)/symbols/_the.symbols: $(IMAGES_OUTPUTDIR)/lib/rt.jar
 	$(RM) -r $(IMAGES_OUTPUTDIR)/symbols/META-INF/sym
 	$(MKDIR) -p $(IMAGES_OUTPUTDIR)/symbols/META-INF/sym
-	$(JAVA) \
-		-Xbootclasspath/a:$(JDK_OUTPUTDIR)/classes \
-		$(JAVAC_JARS) \
+	$(JAVA) $(JAVAC_JARS) \
+	    -bootclasspath $(JDK_OUTPUTDIR)/classes \
 	    -XDprocess.packages -proc:only \
 	    -processor com.sun.tools.javac.sym.CreateSymbols \
 	    -Acom.sun.tools.javac.sym.Jar=$(IMAGES_OUTPUTDIR)/lib/rt.jar \