Add optional start index to Pattern.allMatches.

Add optional start index to Pattern.allMatches.

This is a non-breaking change.
Very few classes implement Pattern, so it's also a mostly non-intrusive change.

If we add startIndex to other methods, like replaceFirstMatch, we can use the extra parameter only for non-zero start indices without breaking existing code.

R=ajohnsen@google.com

Committed: https://code.google.com/p/dart/source/detail?r=39119

[Anders Johnsen, 2014-08-11 11:57:02]

lgtm

https://codereview.chromium.org/460613002/diff/1/tests/language/reg_exp_test....
File tests/language/reg_exp_test.dart (right):

https://codereview.chromium.org/460613002/diff/1/tests/language/reg_exp_test....
tests/language/reg_exp_test.dart:24: // Check that allMatches works with
optional start index.
Should the RegExp '.*' match 

  regExp.allMatches("str", 3), that is, the empty string.

?

[Lasse Reichstein Nielsen, 2014-08-11 12:35:36]

https://codereview.chromium.org/460613002/diff/1/tests/language/reg_exp_test....
File tests/language/reg_exp_test.dart (right):

https://codereview.chromium.org/460613002/diff/1/tests/language/reg_exp_test....
tests/language/reg_exp_test.dart:24: // Check that allMatches works with
optional start index.
It should. I'll add a test for it.

[Lasse Reichstein Nielsen, 2014-08-12 07:13:13]

Committed patchset #2 manually as 39119 (presubmit successful).

[Søren Gjesse, 2014-08-19 07:07:59]

https://codereview.chromium.org/460613002/diff/20001/sdk/lib/core/pattern.dart
File sdk/lib/core/pattern.dart (right):

https://codereview.chromium.org/460613002/diff/20001/sdk/lib/core/pattern.dar...
sdk/lib/core/pattern.dart:25: * match, and initially starting from index zero.
The phrase "and initially starting from index zero" should be changed.