IR: Consistently copyAttributes in DeepCopyIrTreeWithSymbols

This was missing for IrFunctionReferences, which caused problems when
copying default parameters before CallableReferenceLowering in the
JVM_IR backend.

compiler/testData/codegen/box/inlineClasses/mangledDefaultParameterFunction.kt

@@ -0,0 +1,7 @@
+// !LANGUAGE: +InlineClasses
+inline class X(val s: String)
+fun foo(x: X, block: (X) -> String = { it.s }) = block(x)
+
+fun box(): String {
+    return foo(X("OK"))
+}