FE: forbid extension calls on inline functional parameters

Extension receivers are currently implicitly noinline, and changing that
would require modifying the syntax to allow marking them noinline or
crossinline.

^KT-5837 Open
^KT-25787 Fixed
^KT-47965 Fixed
^KT-50107 Fixed
^KT-52403 Fixed

compiler/testData/diagnostics/tests/inline/extensionOnFunction.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !DIAGNOSTICS: -UNUSED_EXPRESSION -UNUSED_PARAMETER -UNUSED_VARIABLE -NOTHING_TO_INLINE
 
 infix fun Function1<Int, Unit>.noInlineExt(p: Int) {}
@@ -16,7 +17,7 @@ inline fun Function1<Int, Unit>.inlineExt() {
 }
 
 inline fun testExtension(s: (p: Int) -> Unit) {
-    s.inlineExt()
+    <!USAGE_IS_NOT_INLINABLE!>s<!>.inlineExt()
 }
 
 inline fun inlineFunWrongExtension(s: (p: Int) -> Unit) {