Tweak classpath for some Javadoc build tasks

This comes up when the Javadoc comments refer to classes in other
subprojects that the corresponding Java code did not actually depend
upon.

com.ibm.wala.cast/build.gradle

@@ -9,6 +9,14 @@ dependencies {
 	compile project(':com.ibm.wala.util')
 }
 
+tasks.javadoc {
+	dependsOn ':com.ibm.wala.cast.js:compileJava'
+
+	doFirst {
+		classpath += files(project(':com.ibm.wala.cast.js').tasks.compileJava)
+	}
+}
+
 def currentJavaHome = org.gradle.internal.jvm.Jvm.current().javaHome
 
 model {

com.ibm.wala.core/build.gradle

@@ -10,3 +10,11 @@ dependencies {
 	compile project(':com.ibm.wala.shrike')
 	compile project(':com.ibm.wala.util')
 }
+
+tasks.javadoc {
+	dependsOn ':com.ibm.wala.dalvik:compileJava'
+
+	doFirst {
+		classpath += files(project(':com.ibm.wala.dalvik').tasks.compileJava)
+	}
+}

com.ibm.wala.util/build.gradle

@@ -4,6 +4,6 @@ tasks.javadoc {
 	dependsOn ':com.ibm.wala.core:compileJava'
 
 	doFirst {
-		classpath += files(new File(project(':com.ibm.wala.core').buildDir, 'classes/java/main'))
+		classpath += files(project(':com.ibm.wala.core').tasks.compileJava)
 	}
 }