JS: do not create var for result if statement is 'someVar = inlineCall()'

js/js.translator/testData/inlineSizeReduction/cases/valAssignment.kt

@@ -0,0 +1,22 @@
+package foo
+
+// CHECK_CONTAINS_NO_CALLS: test
+// CHECK_VARS_COUNT: function=test count=1
+
+inline fun sum(x: Int, y: Int): Int {
+    if (x == 0 || y == 0) return 0
+
+    return x + y
+}
+
+fun test(x: Int, y: Int): Int {
+    val sum: Int
+    sum = sum(x, y)
+    return sum
+}
+
+fun box(): String {
+    assertEquals(3, test(1, 2))
+
+    return "OK"
+}

js/js.translator/testData/inlineSizeReduction/cases/valDeclaration.kt

@@ -0,0 +1,21 @@
+package foo
+
+// CHECK_CONTAINS_NO_CALLS: test
+// CHECK_VARS_COUNT: function=test count=1
+
+inline fun sum(x: Int, y: Int): Int {
+    if (x == 0 || y == 0) return 0
+
+    return x + y
+}
+
+fun test(x: Int, y: Int): Int {
+    val sum = sum(x, y)
+    return sum
+}
+
+fun box(): String {
+    assertEquals(3, test(1, 2))
+
+    return "OK"
+}