JS: change how signature for mangling is generated, taking into account more information. See KT-15285

compiler/backend/src/org/jetbrains/kotlin/codegen/state/KotlinTypeMapper.java

@@ -608,7 +608,7 @@ public class KotlinTypeMapper {
 
                 mapType(argument.getType(), signatureVisitor,
                         argumentMode.toGenericArgumentMode(
-                                TypeMappingUtil.getEffectiveVariance(parameter.getVariance(), argument.getProjectionKind())));
+                                UtilsKt.getEffectiveVariance(parameter.getVariance(), argument.getProjectionKind())));
 
                 signatureVisitor.writeTypeArgumentEnd();
             }

compiler/backend/src/org/jetbrains/kotlin/codegen/state/typeMappingUtil.kt

@@ -18,7 +18,6 @@
 package org.jetbrains.kotlin.codegen.state
 
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
-import org.jetbrains.kotlin.builtins.KotlinBuiltIns.FQ_NAMES as BUILTIN_NAMES
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
 import org.jetbrains.kotlin.load.kotlin.TypeMappingMode
@@ -30,6 +29,8 @@ import org.jetbrains.kotlin.resolve.descriptorUtil.parentsWithSelf
 import org.jetbrains.kotlin.resolve.descriptorUtil.propertyIfAccessor
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.Variance
+import org.jetbrains.kotlin.types.getEffectiveVariance
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns.FQ_NAMES as BUILTIN_NAMES
 
 fun KotlinType.isMostPreciseContravariantArgument(parameter: TypeParameterDescriptor): Boolean =
         // TODO: probably class upper bound should be used
@@ -59,22 +60,6 @@ private fun KotlinType.canHaveSubtypesIgnoringNullability(): Boolean {
     return false
 }
 
-fun getEffectiveVariance(parameterVariance: Variance, projectionKind: Variance): Variance {
-    if (parameterVariance === Variance.INVARIANT) {
-        return projectionKind
-    }
-    if (projectionKind === Variance.INVARIANT) {
-        return parameterVariance
-    }
-    if (parameterVariance === projectionKind) {
-        return parameterVariance
-    }
-
-    // In<out X> = In<*>
-    // Out<in X> = Out<*>
-    return Variance.OUT_VARIANCE
-}
-
 val CallableDescriptor?.isMethodWithDeclarationSiteWildcards: Boolean
     get() {
         if (this !is CallableMemberDescriptor) return false