Implement type inference for try/catch blocks.

pkg/front_end/testcases/inference/try_catch_promotion.dart.outline.expect

Index: pkg/front_end/testcases/inference/try_catch_promotion.dart.outline.expect
diff --git a/pkg/front_end/testcases/inference/try_catch_promotion.dart.outline.expect b/pkg/front_end/testcases/inference/try_catch_promotion.dart.outline.expect
new file mode 100644
index 0000000000000000000000000000000000000000..17ac88f8db0b663470793b48db061332e2a6566f
--- /dev/null
+++ b/pkg/front_end/testcases/inference/try_catch_promotion.dart.outline.expect
@@ -0,0 +1,20 @@
+library test;
+import self as self;
+import "dart:core" as core;
+
+class C extends core::Object {
+  constructor •() → void
+    ;
+}
+class D extends self::C {
+  constructor •() → void
+    ;
+}
+class E extends core::StackTrace {
+  constructor •() → void
+    ;
+}
+static method test(() → void f) → void
+  ;
+static method main() → dynamic
+  ;