Fix control flow graph in the presence of aborting instructions in a try/catch/finally.

tests/language/try_catch4_test.dart

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+// Check that our SSA graph does have the try body a predecessor of a
+// try/finally.
+
+var a;
+
+foo1() {
+  var b = false;
+  var entered = false;
+  while (true) {
+    if (entered) return b;
+    b = 8 == a; // This expression should not be GVN'ed.
+    try {
+      a = 8;
+      return;
+    } finally {
+      b = 8 == a;
+      entered = true;
+      continue;
+    }
+  }
+}
+
+doThrow() { throw 2; }
+
+foo2() {
+  var b = false;
+  var entered = false;
+  while (true) {
+    if (entered) return b;
+    b = 8 == a; // This expression should not be GVN'ed.
+    try {
+      a = 8;
+      doThrow();
+      return;
+    } catch(e) {
+      b = 8 == a;
+      entered = true;
+      continue;
+    }
+  }
+}
+
+foo3() {
+  var b = false;
+  var entered = false;
+  while (true) {
+    if (entered) return b;
+    b = 8 == a; // This expression should not be GVN'ed.
+    try {
+      doThrow();
+    } catch(e) {
+      a = 8;
+      entered = true;
+      return;
+    } finally {
+      b = 8 == a;
+      entered = true;
+      continue;
+    }
+  }
+}
+
+foo4() {
+  var b = false;
+  var entered = false;
+  while (true) {
+    if (entered) return b;
+    b = 8 == a; // This expression should not be GVN'ed.
+    try {
+      a = 8;
+      break;
+    } finally {
+      b = 8 == a;
+      entered = true;
+      continue;
+    }
+  }
+}
+
+foo5() {
+  var b = false;
+  var entered = false;
+  while (true) {
+    if (entered) return b;
+    b = 8 == a; // This expression should not be GVN'ed.
+    try {
+      a = 8;
+      doThrow();
+      break;
+    } catch(e) {
+      b = 8 == a;
+      entered = true;
+      continue;
+    }
+  }
+}
+
+foo6() {
+  var b = false;
+  var entered = false;
+  while (true) {
+    if (entered) return b;
+    b = 8 == a; // This expression should not be GVN'ed.
+    try {
+      doThrow();
+    } catch(e) {
+      a = 8;
+      entered = true;
+      break;
+    } finally {
+      b = 8 == a;
+      entered = true;
+      continue;
+    }
+  }
+}
+
+foo7() {
+  var b = false;
+  var entered = false;
+  while (true) {
+    if (entered) return b;
+    b = 8 == a; // This expression should not be GVN'ed.
+    try {
+      a = 8;
+      continue;
+    } finally {
+      b = 8 == a;
+      entered = true;
+      continue;
+    }
+  }
+}
+
+foo8() {
+  var b = false;
+  var entered = false;
+  while (true) {
+    if (entered) return b;
+    b = 8 == a; // This expression should not be GVN'ed.
+    try {
+      a = 8;
+      doThrow();
+      continue;
+    } catch(e) {
+      b = 8 == a;
+      entered = true;
+      continue;
+    }
+  }
+}
+
+foo9() {
+  var b = false;
+  var entered = false;
+  while (true) {
+    if (entered) return b;
+    b = 8 == a; // This expression should not be GVN'ed.
+    try {
+      doThrow();
+    } catch(e) {
+      a = 8;
+      entered = true;
+      continue;
+    } finally {
+      b = 8 == a;
+      entered = true;
+      continue;
+    }
+  }
+}
+
+main() {
+  a = 0;
+  Expect.isTrue(foo1());
+  a = 0;
+  Expect.isTrue(foo2());
+  a = 0;
+  Expect.isTrue(foo3());
+  a = 0;
+  Expect.isTrue(foo4());
+  a = 0;
+  Expect.isTrue(foo5());
+  a = 0;
+  Expect.isTrue(foo6());
+  a = 0;
+  Expect.isTrue(foo7());
+  a = 0;
+  Expect.isTrue(foo8());
+  a = 0;
+  Expect.isTrue(foo9());
+}