JS: inline safe calls

#KT-6912 fixed

Changelog.md

@@ -1,5 +1,8 @@
-= CHANGELOG =
+# CHANGELOG
 
-== 1.1 ==
+## 1.1
 
-== 1.0.2 ==
+## 1.0.2
+
+### JS
+- Safe calls (`x?.let { it }`) are now inlined

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/InlineJsTestGenerated.java

@@ -299,6 +299,12 @@ public class InlineJsTestGenerated extends AbstractInlineJsTest {
         doTest(fileName);
     }
 
+    @TestMetadata("safeCall.kt")
+    public void testSafeCall() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/inline/cases/safeCall.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("severalClosures.kt")
     public void testSeveralClosures() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/inline/cases/severalClosures.kt");

js/js.translator/src/org/jetbrains/kotlin/js/translate/reference/CallExpressionTranslator.java

@@ -55,7 +55,7 @@ public final class CallExpressionTranslator extends AbstractCallExpressionTransl
 
         JsExpression callExpression = (new CallExpressionTranslator(expression, receiver, context)).translate();
 
-        if (!resolvedCall.isSafeCall() && shouldBeInlined(expression, context)) {
+        if (shouldBeInlined(expression, context)) {
             setInlineCallMetadata(callExpression, expression, resolvedCall, context);
         }
 

js/js.translator/testData/inline/cases/safeCall.kt

@@ -0,0 +1,15 @@
+package foo
+
+// CHECK_CONTAINS_NO_CALLS: sum
+
+inline fun <T : Any, R> T.doLet(f: (T) -> R): R = f(this)
+
+private fun sum(x: Int?, y: Int): Int =
+        x?.doLet { it + y } ?: 0
+
+fun box(): String {
+    assertEquals(5, sum(2, 3))
+    assertEquals(0, sum(null, 3))
+
+    return "OK"
+}