Fix errors. Generalize AST optimizer to handle async methods

teavm-core/src/main/java/org/teavm/javascript/Decompiler.java

@@ -214,6 +214,18 @@ public class Decompiler {
             part.setStatement(getRegularMethodStatement(splitter.getProgram(i), i, splitter.getBlockSuccessors(i)));
             node.getBody().add(part);
         }
+        Program program = method.getProgram();
+        for (int i = 0; i < program.variableCount(); ++i) {
+            node.getVariables().add(program.variableAt(i).getRegister());
+        }
+        Optimizer optimizer = new Optimizer();
+        optimizer.optimize(node, method.getProgram());
+        node.getModifiers().addAll(mapModifiers(method.getModifiers()));
+        int paramCount = Math.min(method.getSignature().length, program.variableCount());
+        for (int i = 0; i < paramCount; ++i) {
+            Variable var = program.variableAt(i);
+            node.getParameterDebugNames().add(new HashSet<>(var.getDebugNames()));
+        }
         return node;
     }
 

teavm-core/src/main/java/org/teavm/javascript/Optimizer.java

@@ -15,6 +15,8 @@
  */
 package org.teavm.javascript;
 
+import org.teavm.javascript.ast.AsyncMethodNode;
+import org.teavm.javascript.ast.AsyncMethodPart;
 import org.teavm.javascript.ast.RegularMethodNode;
 import org.teavm.model.Program;
 
@@ -40,4 +42,27 @@ public class Optimizer {
             method.getVariables().set(i, i);
         }
     }
+
+    public void optimize(AsyncMethodNode method, Program program) {
+        ReadWriteStatsBuilder stats = new ReadWriteStatsBuilder(method.getVariables().size());
+        stats.analyze(program);
+        OptimizingVisitor optimizer = new OptimizingVisitor(stats);
+        for (AsyncMethodPart part : method.getBody()) {
+            part.getStatement().acceptVisitor(optimizer);
+            part.setStatement(optimizer.resultStmt);
+        }
+        int paramCount = method.getReference().parameterCount();
+        UnusedVariableEliminator unusedEliminator = new UnusedVariableEliminator(paramCount, method.getVariables());
+        for (AsyncMethodPart part : method.getBody()) {
+            part.getStatement().acceptVisitor(unusedEliminator);
+        }
+        method.getVariables().subList(unusedEliminator.lastIndex, method.getVariables().size()).clear();
+        RedundantLabelEliminator labelEliminator = new RedundantLabelEliminator();
+        for (AsyncMethodPart part : method.getBody()) {
+            part.getStatement().acceptVisitor(labelEliminator);
+        }
+        for (int i = 0; i < method.getVariables().size(); ++i) {
+            method.getVariables().set(i, i);
+        }
+    }
 }

teavm-core/src/main/java/org/teavm/javascript/Renderer.java

@@ -1455,7 +1455,7 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
                         break;
                 }
                 if (expr.getAsyncTarget() != null) {
-                    writer.append(',').ws().append("$part_").append(expr.getAsyncTarget());
+                    writer.append(',').ws().append("$rt_continue($part_").append(expr.getAsyncTarget()).append(')');
                 }
                 writer.append(')');
                 if (lastCallSite != null) {

teavm-core/src/main/java/org/teavm/model/util/AsyncProgramSplitter.java

@@ -57,6 +57,7 @@ public class AsyncProgramSplitter {
             int end = step.sourceIndex;
             boolean asyncOccured = false;
             for (int i = step.sourceIndex; i < sourceBlock.getInstructions().size(); ++i) {
+                end = i;
                 Instruction insn = sourceBlock.getInstructions().get(i);
                 if (insn instanceof InvokeInstruction) {
                     InvokeInstruction invoke = (InvokeInstruction)insn;

teavm-core/src/main/resources/org/teavm/javascript/runtime.js

@@ -402,6 +402,19 @@ function $rt_stringPool(strings) {
 function $rt_s(index) {
     return $rt_stringPool_instance[index];
 }
+var $rt_continueCounter = 0;
+function $rt_continue(f) {
+   if ($rt_continueCounter++ == 10) {
+       $rt_continueCounter = 0;
+       var self = f;
+       var args = arguments;
+       setTimeout(function() {
+           f.apply(self, args);
+       }, 0);
+   } else {
+       return f;
+   }
+}
 
 function $dbg_repr(obj) {
     return obj.toString ? obj.toString() : "";