JVM IR: get rid of toIrBasedKotlinType in MethodSignatureMapper

Commonize (in terms of TypeSystemCommonBackendContext implementations
for KotlinType/IrType) code that computes optimal TypeMappingMode to
apply to different positions where inline class types can be present.

compiler/testData/codegen/box/callableReference/genericConstructorReference.kt

@@ -1,7 +1,5 @@
 // DONT_TARGET_EXACT_BACKEND: WASM
 // WASM_MUTE_REASON: BINDING_RECEIVERS
-
-// IGNORE_BACKEND_FIR: JVM_IR
 // KT-42025
 
 open class L<LL>(val ll: LL)
@@ -98,4 +96,4 @@ fun box(): String {
     val ipl = i.readP(Rec("OK"))
 
     return ipl.ll
-}
+}