Merge pull request #450 from cscott/promise-improvements

test/built-ins/Promise/all/S25.4.4.1_A3.1_T3.js

test/built-ins/Promise/all/S25.4.4.1_A5.1_T1.js

test/built-ins/Promise/executor-function-extensible.js

test/built-ins/Promise/executor-function-length.js

test/built-ins/Promise/executor-function-name.js

test/built-ins/Promise/executor-function-nonconstructor.js

test/built-ins/Promise/executor-function-prototype.js

test/built-ins/Promise/race/S25.4.4.3_A2.2_T3.js

test/built-ins/Promise/race/S25.4.4.3_A4.1_T1.js

test/built-ins/Promise/race/S25.4.4.3_A4.1_T2.js

test/built-ins/Promise/symbol-species.js