Restrict yield outside generators in strict mode

* Move some yield/generic tests from compress/harmony.js to
  compress/yield.js
 * Adjust error messages to conform ecmascript standards

test/compress/harmony.js

@@ -449,110 +449,4 @@ regression_cannot_use_of: {
         x.of;
         foo();  /* Label statement missing? No prob. */
     }
-}
-
-generators: {
-    input: {
-        function* fn() {};
-    }
-    expect_exact: "function*fn(){}"
-}
-
-generators_yield: {
-    input: {
-      function* fn() {
-        yield remote();
-      }
-    }
-    expect_exact: "function*fn(){yield remote()}"
-}
-
-generators_yield_assign: {
-    input: {
-      function* fn() {
-          var x = {};
-          x.prop = yield 5;
-      }
-    }
-    expect_exact: "function*fn(){var x={};x.prop=yield 5}"
-}
-
-generator_yield_undefined: {
-    input: {
-        function* fn() {
-            yield;
-        }
-    }
-    expect_exact: "function*fn(){yield}"
-}
-
-yield_optimize_expression: {
-    options = {
-    }
-    input: {
-        function* f1() { yield; }
-        function* f2() { yield undefined; }
-        function* f3() { yield null; }
-        function* f4() { yield* undefined; }
-    }
-    expect: {
-        function* f1() { yield }
-        function* f2() { yield; }
-        function* f3() { yield null; }
-        function* f4() { yield* void 0; }
-    }
-}
-
-yield_statements: {
-    input: {
-        function* fn() {
-            var a = (yield 1) + (yield 2);
-            var b = (yield 3) === (yield 4);
-            var c = (yield 5) << (yield 6);
-            var d = yield 7;
-            var e = (yield 8) ? yield 9 : yield 10;
-            var f = -(yield 11);
-        }
-    }
-    expect_exact: "function*fn(){var a=(yield 1)+(yield 2);var b=(yield 3)===(yield 4);var c=(yield 5)<<(yield 6);var d=yield 7;var e=(yield 8)?yield 9:yield 10;var f=-(yield 11)}"
-}
-
-yield_as_identifier_in_function_in_generator: {
-    input: {
-        var g = function*() {
-            function h() {
-                yield = 1;
-            }
-        };
-    }
-    expect: {
-        var g = function*() {
-            function h() {
-                yield = 1;
-            }
-        };
-    }
-}
-
-yield_before_punctuators: {
-    input: {
-        iter = (function*() {
-            assignmentResult = [ x = yield ] = value;
-        })();
-        function* g1() { (yield) }
-        function* g2() { [yield] }
-        function* g3() { return {yield} } // Added return to avoid {} drop
-        function* g4() { yield, yield; }
-        function* g5() { (yield) ? yield : yield; }
-    }
-    expect: {
-        iter = (function*() {
-            assignmentResult = [ x = yield ] = value;
-        })();
-        function* g1() { (yield) }
-        function* g2() { [yield] }
-        function* g3() { return {yield} }
-        function* g4() { yield, yield; }
-        function* g5() { (yield) ? yield : yield; }
-    }
 }