Test that clashing signatures are not reported when conflicting overloads are present in CLI

compiler/testData/cli/jvm/conflictingOverloads.args

@@ -0,0 +1,4 @@
+-src
+$TESTDATA_DIR$/conflictingOverloads.kt
+-output
+$TEMP_DIR$

compiler/testData/cli/jvm/conflictingOverloads.kt

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+fun a(): List<Int> = null!!
+fun a(): List<String> = null!!

compiler/testData/cli/jvm/conflictingOverloads.out

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+ERROR: $TESTDATA_DIR$/conflictingOverloads.kt: (1, 1) 'internal fun a(): kotlin.List<kotlin.Int>' is already defined in root package
+ERROR: $TESTDATA_DIR$/conflictingOverloads.kt: (2, 1) 'internal fun a(): kotlin.List<kotlin.String>' is already defined in root package
+COMPILATION_ERROR