Add tests for converting expressions of function types to suspending functional types

compiler/testData/codegen/box/suspendConversion/suspendConversionOnVarargElements.kt

@@ -0,0 +1,27 @@
+// FIR_IDENTICAL
+// !LANGUAGE: +SuspendConversion
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+fun useSuspendVararg(vararg sfn: suspend () -> Unit) {}
+
+fun testSuspendConversionInVarargElementsSome(
+    sf1: suspend () -> Unit,
+    f2: () -> Unit,
+    sf3: suspend () -> Unit
+) {
+    useSuspendVararg(sf1, f2, sf3)
+}
+
+fun testSuspendConversionInVarargElementsAll(
+    f1: () -> Unit,
+    f2: () -> Unit,
+    f3: () -> Unit
+) {
+    useSuspendVararg(f1, f2, f3)
+}
+
+fun box(): String {
+    testSuspendConversionInVarargElementsSome({}, {}, {})
+    testSuspendConversionInVarargElementsAll({}, {}, {})
+    return "OK"
+}