JS backend: added tests for infix calls.

#KT-3998   in progress
 #EA-56241 in progress

js/js.translator/testData/expression/function/cases/infixCall.kt

@@ -0,0 +1,23 @@
+// EA-56241
+package foo
+
+fun Int.foo(a: Int) = this + a
+
+val bar = { Int.(a: Int) -> this * a }
+
+fun test(op: Int.(Int) -> Int) = 3 op 20
+
+fun assertEquals<T>(expected: T, actual: T) {
+    if (expected != actual) throw Exception("expected: $expected, actual: $actual")
+}
+
+fun box(): String {
+    val op = { Int.(a: Int) -> this / a }
+
+    assertEquals(41, 34 foo 7)
+    assertEquals(28, 4 bar 7)
+    assertEquals(-17, test { this - it })
+    assertEquals(7, 49 op 7)
+
+    return "OK"
+}