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/expressions/argumentMappedWithError.kt.txt

@@ -5,7 +5,7 @@ fun <R : Number> Number.convert(): R {
 fun foo(arg: Number) {
 }
 
-fun main(args: Array<String>) {
+fun runMe(args: Array<String>) {
   val x: Int = 0
   foo(arg = x.convert<Number>())
 }