Introduce deprecated helpers to ease migration

libraries/tools/kotlin-stdlib-gen/src/templates/dsl/MemberBuilder.kt

@@ -59,6 +59,8 @@ class MemberBuilder(
     var deprecate: Deprecation? = null; private set
     var since: String? = null; private set
     var platformName: String? = null; private set
+    @Deprecated("Use platforms when building template")
+    var jvmOnly: Boolean = false
 
     var visibility: String? = null; private set
     var external: Boolean = false; private set
@@ -102,6 +104,8 @@ class MemberBuilder(
         signature = value
     }
     fun returns(type: String) { returns = type }
+    @Deprecated("Use specialFor", ReplaceWith("specialFor(*fs) { returns(run(valueBuilder)) }"))
+    fun returns(vararg fs: Family, valueBuilder: () -> String) = specialFor(*fs) { returns(run(valueBuilder)) }
 
     fun typeParam(typeParameterName: String) {
         typeParams += typeParameterName
@@ -119,6 +123,9 @@ class MemberBuilder(
         doc = valueBuilder(DocExtensions)
     }
 
+    @Deprecated("Use specialFor", ReplaceWith("specialFor(*fs) { doc(valueBuilder) }"))
+    fun doc(vararg fs: Family, valueBuilder: DocExtensions.() -> String) = specialFor(*fs) { doc(valueBuilder) }
+
     fun body(valueBuilder: () -> String) {
         body = valueBuilder()
     }
@@ -323,6 +330,11 @@ class MemberBuilder(
             builder.append("@kotlin.internal.InlineOnly").append('\n')
         }
 
+        if (jvmOnly) {
+            builder.append("@kotlin.jvm.JvmVersion").append('\n')
+        }
+
+
         listOfNotNull(
                 visibility ?: "public",
                 "expect".takeIf { headerOnly },