IR text tests: Unmute tests that have main function

Don't use `main` function in these tests, because `main` function
has specific mangling rules in JVM. Use other function name.

^KT-57755

compiler/testData/ir/irText/firProblems/localCompanion.kt

@@ -1,9 +1,6 @@
 // FIR_IDENTICAL
 
-// MUTE_SIGNATURE_COMPARISON_K2: JVM_IR
-// ^ KT-57755: Fix computing a mangled name for the `main` function
-
-fun main() {
+fun runMe() {
     class Foo {
         @Suppress("WRONG_MODIFIER_CONTAINING_DECLARATION")
         companion object {