IR: remove default undefined offsets from createTemporaryVariableDeclaration

Scope.createTemporaryVariableDeclaration has default values for
startOffset and endOffset parameters, which are UNDEFINED_OFFSET.

This is error-prone. Caller should typically be able to pass proper
offsets. If not, let using undefined offsets at least be explicit.

Remove default values for startOffset and endOffset parameters in
Scope.createTemporaryVariableDeclaration

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/builders/Scope.kt

@@ -54,8 +54,8 @@ class Scope(val scopeOwnerSymbol: IrSymbol) {
         nameHint: String? = null,
         isMutable: Boolean = false,
         origin: IrDeclarationOrigin = IrDeclarationOrigin.IR_TEMPORARY_VARIABLE,
-        startOffset: Int = UNDEFINED_OFFSET,
-        endOffset: Int = UNDEFINED_OFFSET
+        startOffset: Int,
+        endOffset: Int
     ): IrVariable {
         val name = Name.identifier(getNameForTemporary(nameHint))
         return IrVariableImpl(