Optimize js-jsx--matching-close-tag-pos

This function’s performance was having a noticeable impact when
editing large JSX structures.  Improve its performance
slightly (elapsed time will be cut in half according to ELP).

* lisp/progmodes/js.el (js-jsx--tag-re): Remove.
(js-jsx--matched-tag-type): Simplify implementation with respect to
the new implementation of js-jsx--matching-close-tag-pos.
(js-jsx--self-closing-re): Simplify regexp slightly in sync with a
generally simpler matching algorithm.
(js-jsx--matching-close-tag-pos): Optimize matching algorithm by using
multiple simple regexp searches, rather than one big complex search.

* test/manual/indent/jsx-unclosed-2.jsx: Use the term “inequality” and
add a test for a possible parsing foible.

1 files changed, 6 insertions, 1 deletions

diff --git a/test/manual/indent/jsx-unclosed-2.jsx b/test/manual/indent/jsx-unclosed-2.jsx
index 8db25aa67f1..9d80a2e9ae2 100644
--- a/test/manual/indent/jsx-unclosed-2.jsx
+++ b/test/manual/indent/jsx-unclosed-2.jsx
@@ -6,10 +6,15 @@
 // The following tests go below any comments to avoid including
 // misindented comments among the erroring lines.
 
-// Don’t misinterpret equality operators as JSX.
+// Don’t misinterpret inequality operators as JSX.
 for (; i < length;) void 0
 if (foo > bar) void 0
 
+// Don’t misintrepet inequalities within JSX, either.
+<div>
+  {foo < bar}
+</div>
+
 // Don’t even misinterpret unary operators as JSX.
 if (foo < await bar) void 0
 while (await foo > bar) void 0