[JS IR] [Wasm] Extract InlineClassesUtils into CommonBackendContext

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/CommonBackendContext.kt

@@ -11,6 +11,8 @@ import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.builders.IrBuilderWithScope
 import org.jetbrains.kotlin.ir.builders.irCall
 import org.jetbrains.kotlin.ir.builders.irString
+import org.jetbrains.kotlin.ir.declarations.IrClass
+import org.jetbrains.kotlin.ir.declarations.IrConstructor
 import org.jetbrains.kotlin.ir.declarations.IrDeclarationOrigin
 import org.jetbrains.kotlin.ir.declarations.IrFile
 import org.jetbrains.kotlin.ir.expressions.IrCall
@@ -19,6 +21,9 @@ import org.jetbrains.kotlin.ir.expressions.IrStatementOrigin
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
 import org.jetbrains.kotlin.ir.symbols.IrFileSymbol
 import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
+import org.jetbrains.kotlin.ir.types.IrType
+import org.jetbrains.kotlin.ir.util.fqNameWhenAvailable
+import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstanceOrNull
 
 interface LoggingContext {
     var inVerbosePhase: Boolean
@@ -67,4 +72,34 @@ interface CommonBackendContext : BackendContext, LoggingContext {
 
     val optimizeNullChecksUsingKotlinNullability: Boolean
         get() = true
+
+    /**
+     * See [InlineClassesUtils].
+     */
+    val inlineClassesUtils: InlineClassesUtils
+        get() = DefaultInlineClassesUtils
 }
+
+/**
+ * Provides means for determining if a class should be treated as an inline/value class.
+ *
+ * In certain cases (for compatibility reasons) we don't want to mark a class as `inline`, but still want to treat it as one.
+ *
+ * See [org.jetbrains.kotlin.ir.backend.js.utils.JsInlineClassesUtils].
+ */
+interface InlineClassesUtils {
+    /**
+     * Should this class be treated as inline class?
+     */
+    fun isClassInlineLike(klass: IrClass): Boolean = klass.isInline
+
+    /**
+     * Unlike [org.jetbrains.kotlin.ir.util.getInlineClassUnderlyingType], doesn't use [IrClass.inlineClassRepresentation] because
+     * for some reason it can be called for classes which are not inline, e.g. `kotlin.Double`.
+     */
+    fun getInlineClassUnderlyingType(irClass: IrClass): IrType =
+        irClass.declarations.firstIsInstanceOrNull<IrConstructor>()?.takeIf { it.isPrimary }?.valueParameters?.get(0)?.type
+            ?: error("Class has no primary constructor: ${irClass.fqNameWhenAvailable}")
+}
+
+object DefaultInlineClassesUtils : InlineClassesUtils