[PATCH 6/6] RelNotes: add more notes about PCRE in 2.14

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

We were missing any mention that:

 - PCRE is now faster with JIT
 - That it's now faster than the other regex backends
 - That therefore you might want to use it by default, but beware of
   the incompatible syntax.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 Documentation/RelNotes/2.14.0.txt | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/Documentation/RelNotes/2.14.0.txt b/Documentation/RelNotes/2.14.0.txt
index fb6a3dba31..a6a1cb963b 100644
--- a/Documentation/RelNotes/2.14.0.txt
+++ b/Documentation/RelNotes/2.14.0.txt
@@ -88,7 +88,16 @@ UI, Workflows & Features
    learned to say "it's a pathspec" a bit more often when the syntax
    looks like so.
 
- * Update "perl-compatible regular expression" support to enable JIT.
+ * Update "perl-compatible regular expression" support to enable
+   JIT.
+
+   This makes grep.patternType=perl (and -P and --perl-regexp) much
+   faster for "git grep" and "git log", and is generally faster than
+   the system's POSIX regular expression implementation. Users
+   concerned with "git grep" performance or "git log --grep"
+   performance might want to try setting grep.patternType=perl. Note
+   that the syntax isn't compatible with git's default of
+   grep.patternType=basic.
 
  * "filter-branch" learned a pseudo filter "--setup" that can be used
    to define common functions/variables that can be used by other
-- 
2.13.2.932.g7449e964c