fix readability regressions from previous block-scope CL

also reverts the simple incremental compile code, it wasn't aware of our own compiler's version.

also fixes a warning from analyzer

R=leafp@google.com

Review URL: https://codereview.chromium.org/1305413006 .

Author: John Messerly

lib/src/codegen/js_codegen.dart

@@ -1767,9 +1767,9 @@ class JSCodegenVisitor extends GeneralizingAstVisitor with ClosureAnnotator {
   @override
   JS.Block visitBlockFunctionBody(BlockFunctionBody node) {
     var initArgs = _emitArgumentInitializers(node.parent);
-    var block = visitBlock(node.block);
-    if (initArgs != null) return new JS.Block([initArgs, block]);
-    return block;
+    var stmts = _visitList(node.block.statements) as List<JS.Statement>;
+    if (initArgs != null) stmts.insert(0, initArgs);
+    return new JS.Block(stmts);
   }
 
   @override
@@ -2932,7 +2932,8 @@ class JSCodegenVisitor extends GeneralizingAstVisitor with ClosureAnnotator {
       }
     }
 
-    body.add(_visit(node.body));
+    body.add(
+        new JS.Block(_visitList(node.body.statements) as List<JS.Statement>));
     _catchParameter = savedCatch;
     return _statement(body);
   }

lib/src/compiler.dart

@@ -173,20 +173,6 @@ class BatchCompiler extends AbstractCompiler {
     }
 
     if (_jsGen != null) {
-      // TODO(jmesserly): full incremental support would avoid checking as well,
-      // however, we'd lose compiler messages in that case.
-
-      // Note: analyzer's modification stamp is millisecondsSinceEpoch
-      int lastModifyTime = unitElements
-          .map((e) => context.getModificationStamp(e.source))
-          .reduce(math.max);
-      var outFile = new File(getOutputPath(library.source.uri));
-      if (outFile.existsSync() &&
-          outFile.lastModifiedSync().millisecondsSinceEpoch >= lastModifyTime) {
-        // Output already up to date.
-        return;
-      }
-
       var unit = units.first;
       var parts = units.skip(1).toList();
       _jsGen.generateLibrary(new LibraryUnit(unit, parts));

lib/src/js/nodes.dart

@@ -285,7 +285,7 @@ class Block extends Statement {
   Block(this.statements, {this.isScope: false}) {
     assert(!statements.any((s) => s is! Statement));
   }
-  Block.empty() : this.statements = <Statement>[];
+  Block.empty() : statements = <Statement>[], isScope = false;
 
   accept(NodeVisitor visitor) => visitor.visitBlock(this);
   void visitChildren(NodeVisitor visitor) {

test/codegen/expect/sunflower/sunflower.html

@@ -51,8 +51,8 @@ <h1>drfibonacci's Sunflower Spectacular</h1>
 <script src="../dev_compiler/runtime/dart/mirrors.js"></script>
 <script src="../dev_compiler/runtime/dart/_js_mirrors.js"></script>
 <script src="../dev_compiler/runtime/dart/js.js"></script>
-<script src="dom.js"></script>
 <script src="circle.js"></script>
+<script src="dom.js"></script>
 <script src="painter.js"></script>
 <script src="sunflower.js"></script>
 <script>dart_library.start('sunflower/sunflower');</script>