Support generating "deprecated" functions.

libraries/tools/kotlin-stdlib-gen/src/templates/Engine.kt

@@ -41,6 +41,9 @@ class GenericFunction(val signature: String) : Comparable<GenericFunction> {
     val buildFamilies = HashSet<Family>(defaultFamilies.toList())
     private val buildPrimitives = HashSet<PrimitiveType>(PrimitiveType.values().toList())
 
+    var deprecate: String = ""
+    val deprecates = HashMap<Family, String>()
+
     var doc: String = ""
     val docs = HashMap<Family, String>()
 
@@ -73,6 +76,16 @@ class GenericFunction(val signature: String) : Comparable<GenericFunction> {
         }
     }
 
+    fun deprecate(vararg families: Family, b: () -> String) {
+        if (families.isEmpty())
+            deprecate = b()
+        else {
+            for (f in families) {
+                deprecates[f] = b()
+            }
+        }
+    }
+
     fun returns(vararg families: Family, b: () -> String) {
         if (families.isEmpty())
             defaultReturnType = b()
@@ -225,6 +238,10 @@ class GenericFunction(val signature: String) : Comparable<GenericFunction> {
             }
             builder.append(" */\n")
         }
+        val deprecated = deprecates[f] ?: deprecate
+        if (deprecated != "") {
+            builder.append("deprecated(\"$deprecated\")\n")
+        }
 
         builder.append("public ")
         if (inlineFamilies[f] ?: defaultInline)