fix KT-10064 Regression: Error with multiple main functions within a single package

#KT-10064 Fixed

jps-plugin/testData/incremental/pureKotlin/mainRedeclaration/a.kt

@@ -0,0 +1,3 @@
+package foo
+
+fun main(args: Array<String>) = println("a")

jps-plugin/testData/incremental/pureKotlin/mainRedeclaration/a.kt.new

@@ -0,0 +1,3 @@
+package foo
+
+fun main(args: Array<String>) = println("A")

jps-plugin/testData/incremental/pureKotlin/mainRedeclaration/b.kt

@@ -0,0 +1,3 @@
+package foo
+
+fun main(args: Array<String>) = println("b")

jps-plugin/testData/incremental/pureKotlin/mainRedeclaration/build.log

@@ -0,0 +1,7 @@
+Cleaning output files:
+out/production/module/META-INF/module.kotlin_module
+out/production/module/foo/AKt.class
+End of files
+Compiling files:
+src/a.kt
+End of files