* Move decimalToHexString into harness instead of duplicating it in multiple files

* Optimize decimalToHexString and support numbers greater than 65535

* Replace alternative decimalToHexString function with include for decimalToHexString.js

* Add decimalToHex2String to return the string representation of a two-digit hex-number

* Replace decimalToHex2String with decimalToPercentHexString to return the percent hex-encoded string of a two-digit hex-number

* Replace two String.fromCharCode calls with a single call

* Further reduce string concatentations in decodeURI[Component] tests

* Remove unnecessary Test262Error error handling in catch-clauses

* Remove try/catch wrappings in decodeURI/encodeURI tests

Proposal: https://github.com/tc39/proposal-regexp-unicode-property-escapes

These tests have been generated by the script at https://github.com/mathiasbynens/unicode-property-escapes-tests. They check all the properties and values that should be supported by implementations against the symbols they’re supposed to match. False positives are detected as well.

Ref. #950.
Ref. https://github.com/tc39/proposal-regexp-unicode-property-escapes/issues/4.

Ref https://github.com/tc39/test262/pull/879#discussion_r104128520

Ref tc39/ecma262#807

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>

Because expectations regarding error "phase" are now expressed via test
meta-data, the test runner may now enforce this requirement on negative
tests.

Remove the "NotEarlyError" from the project source. This reduces the
amount of domain knowledge required to author tests and lessens the
potential for inconsistencies between tests.

Due to specs approximation values, some tests are invalid as the harness
helpers rely on another approximated values as Math.LN2.

Update testTypedArrayConversions to require byteConversionValues

Ensure that NaN values are canonicalized consistently by all invocations
of SetValueInBuffer. Also ensure that `%TypedArray%.prototype.set` and
`%TypedArray%.prototype.slice` preserve the bit-level encoding of the
source data.

Use a set of experimentally-derived expressions known to produce NaN
values with distinct bit patterns in various platforms.

Modify the regular expression for native functions' toString value to
satisfy all test cases. Correct the test file's reference to the harness
file. Re-format the test file's assertions to aid debugging in the event
of failure.

The millisecond representation of a given Date instance is dependent on
the local system's time zone settings. In order to pass consistently
across contexts, tests for this value must take the system configuration
into account.

Introduce a test harness utility function to encapsulate these concerns.
Re-use this function across all test files that assert the exact
millisecond representation of Date instances.

See the proposal at
https://tc39.github.io/Function-prototype-toString-revision/

The harness file `Test262Error.js` has not contained executable code since it
was introduced in this project [1]. The definition of the `Test262Error`
function has consistently been located in the `sta.js` harness file which test
runners are expected to inject into the test environment.

Remove the file and all references to it.

[1] See commit c33bf0e0

ECMAScript 2015 introduced tail call optimization for function calls
occuring in a number of positions in the grammar. Assert expected
behavior by triggering a large (but configurable) number of recursive
function calls in these positions. Compliant runtimes will execute such
programs without error; non-compliant runtimes are expected to fail
these tests by throwing an error or crashing when system resources are
exhausted.

- lastIndex in RegExp.prototype[Symbol.split]: tc39/ecma262@08b4756747f9c967058239df627da544412740a6
- Missing number conversion in DataView.prototype.setXXX: tc39/ecma262@4f875fe96dcbd5e6363dd3d5b510cd5109199f5b
- Negative zero byteoffset in TypedArray: tc39/ecma262@2d1ed20db778e8f69f66ba76b351b9322fd38495
- EvalDeclarationInstantiation throws TypeError: tc39/ecma262@2be6968715946a4763f6ca8633e311ab7ce63577
- BindingRestElement allows BindingPattern: tc39/ecma262@d322357e6be95bc4bd3e03f5944a736aac55fa50
- Eval in parameters with computed property keys: tc39/ecma262@04e2e9b7197a33612202e85065e3f8d8385fbcef
- Use strict with non-simple parameters: tc39/ecma262@15b0db41edd0e519e94668bf13765fe458840766
- __proto__ in strict mode: tc39/ecma262@5c1984334d6d42538527bd022e68bfbfee5cb652

Fixes #405

Expected/actual values should be delimited in a way that
isn't confusable with actual string quotes " '

Some JavaScript source files are only relevant in the context of the
Test262 website. They should not be explicitly included by individual
tests, so their presence in the `harness/` directory alongside "include"
files is misleading.

Move the scripts to a location within the `website/` directory to
better-reflect their intended use. Update the relevant HTML templates
with the new locations.

Although test files once expressed dependencies on external files using
a global `$INCLUDE` function, that pattern was removed in favor of
declarative meta-data [1].

Remove the associated logic from the Python runner and the browser.

[1] See commit d4354d14.

The `fnExists` function defines a generic way to determine if any number
of values are function instances. Because it is only used by a single
test, the additional complexity required by the generalized code (and
the organizational drawbacks to maintaining another "include" file) are
not justified. Remove the file and update the test to assert the
function's existence directly.