Tweak when ^:dprecated var warnings are emitted

This patch changes the behavior of var deprecation warnings to limit
false positives when loading deprecated namespaces. Specifically, when
compiling a deprecated namespace, uses of vars in the current namespace
or in any other deprecated namespace will not emit deprecation warnings.

This should hugely reduce warning noise, restricting deprecated warnings
to deprecated/non-deprecated contact points which is where they are
appropriate.

src/jvm/clojure/lang/Compiler.java

@@ -378,6 +378,15 @@ static boolean isPedantic() {
     return RT.booleanCast(getCompilerOption(pedanticKey));
   }
 
+  static boolean isDeprecated(Var v) {
+    return (RT.booleanCast(RT.get(v.meta(), deprecatedKey, false))
+            || isDeprecated(v.ns));
+  }
+
+  static boolean isDeprecated(Namespace n) {
+    return RT.booleanCast(RT.get(n.meta(), deprecatedKey, false));
+  }
+
   static Symbol resolveSymbol(Symbol sym) {
     //already qualified or classname?
     if (sym.name.indexOf('.') > 0) {
@@ -6780,16 +6789,19 @@ private static Expr analyzeSymbol(Symbol sym) {
 
       String loc = String.format(" (%s:%d:%d)", SOURCE.get(), lineDeref(), columnDeref());
       Object meta = RT.meta(v);
+      Namespace nsc = (Namespace) RT.CURRENT_NS.get();
 
-      if ((RT.booleanCast(RT.get(meta, deprecatedKey, false))
-           || (RT.booleanCast(RT.get(v.ns, deprecatedKey, false))
-               && !Util.equiv(v.ns, RT.CURRENT_NS.get())))
+      if (isDeprecated(v)
+          // Mask out warnings when the whole ns is deprecated
+          // Also handles the case of both nss being deprecated
+          && !isDeprecated(nsc)
+          // Mask out warnings when not pedantic
           && isPedantic()) {
         RT.errPrintWriter().println("Warning: using deprecated var: " + v.toString() + loc);
       }
 
       if (RT.booleanCast(RT.get(meta, privateKey, false))
-          && !Util.equals(RT.CURRENT_NS.get(), v.ns)
+          && !Util.equals(nsc, v.ns)
           && isPedantic()) {
         RT.errPrintWriter().println("Warning: using private var in other ns: " + v.toString() + loc);
       }