patch 9.1.0694: matchparen is slow on a long line

Problem:  The matchparen plugin is slow on a long line.
Solution: Don't use a regexp to get char at and before cursor.
          (zeertzjq)

Example:

```vim
  call setline(1, repeat(' foobar', 100000))
  runtime plugin/matchparen.vim
  normal! $hhhhhhhh
```

closes: #15568

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/dumps/Test_matchparen_mbyte_1.dump b/src/testdir/dumps/Test_matchparen_mbyte_1.dump
new file mode 100644
index 0000000..f5df150
--- /dev/null
+++ b/src/testdir/dumps/Test_matchparen_mbyte_1.dump
@@ -0,0 +1,10 @@
+>a+0&#ffffff0@7|(*&| +&@64
+|b@3|)*&|c+&@1| @66
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|1|,|1| @10|A|l@1| 
diff --git a/src/testdir/dumps/Test_matchparen_mbyte_2.dump b/src/testdir/dumps/Test_matchparen_mbyte_2.dump
new file mode 100644
index 0000000..0e4e6e8
--- /dev/null
+++ b/src/testdir/dumps/Test_matchparen_mbyte_2.dump
@@ -0,0 +1,10 @@
+|a+0&#ffffff0@7>(*0&#40ffff15| +0&#ffffff0@64
+|b@3|)*0&#40ffff15|c+0&#ffffff0@1| @66
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|1|,|9| @10|A|l@1| 
diff --git a/src/testdir/dumps/Test_matchparen_mbyte_3.dump b/src/testdir/dumps/Test_matchparen_mbyte_3.dump
new file mode 100644
index 0000000..85c462a
--- /dev/null
+++ b/src/testdir/dumps/Test_matchparen_mbyte_3.dump
@@ -0,0 +1,10 @@
+|a+0&#ffffff0@7|(*&| +&@64
+|b@3|)*&|c+&>c| @66
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|2|,|9|-|8| @8|A|l@1| 
diff --git a/src/testdir/dumps/Test_matchparen_mbyte_4.dump b/src/testdir/dumps/Test_matchparen_mbyte_4.dump
new file mode 100644
index 0000000..45f5d08
--- /dev/null
+++ b/src/testdir/dumps/Test_matchparen_mbyte_4.dump
@@ -0,0 +1,10 @@
+|a+0&#ffffff0@7|(*0&#40ffff15| +0&#ffffff0@64
+|b@3>)*0&#40ffff15|c+0&#ffffff0@1| @66
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|2|,|5| @10|A|l@1| 
diff --git a/src/testdir/dumps/Test_matchparen_mbyte_5.dump b/src/testdir/dumps/Test_matchparen_mbyte_5.dump
new file mode 100644
index 0000000..45c3bfa
--- /dev/null
+++ b/src/testdir/dumps/Test_matchparen_mbyte_5.dump
@@ -0,0 +1,10 @@
+|a+0&#ffffff0@7|(*&| +&@64
+>b@3|)*&|c+&@1| @66
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|2|,|1| @10|A|l@1| 
diff --git a/src/testdir/dumps/Test_matchparen_mbyte_6.dump b/src/testdir/dumps/Test_matchparen_mbyte_6.dump
new file mode 100644
index 0000000..8064a98
--- /dev/null
+++ b/src/testdir/dumps/Test_matchparen_mbyte_6.dump
@@ -0,0 +1,10 @@
+|a+0&#ffffff0@7|(*0&#40ffff15> +0&#ffffff0@64
+|b@3|)*0&#40ffff15|c+0&#ffffff0@1| @66
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|-+2#0000000&@1| |I|N|S|E|R|T| |-@1| +0&&@44|1|,|1|2|-|1@1| @6|A|l@1| 
diff --git a/src/testdir/dumps/Test_matchparen_mbyte_7.dump b/src/testdir/dumps/Test_matchparen_mbyte_7.dump
new file mode 100644
index 0000000..4d8c647
--- /dev/null
+++ b/src/testdir/dumps/Test_matchparen_mbyte_7.dump
@@ -0,0 +1,10 @@
+|a+0&#ffffff0@7|(*&| +&@64
+|b@3|)*&|c+&@1> @66
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|-+2#0000000&@1| |I|N|S|E|R|T| |-@1| +0&&@44|2|,|1|0|-|9| @7|A|l@1| 
diff --git a/src/testdir/dumps/Test_matchparen_mbyte_8.dump b/src/testdir/dumps/Test_matchparen_mbyte_8.dump
new file mode 100644
index 0000000..c3699fd
--- /dev/null
+++ b/src/testdir/dumps/Test_matchparen_mbyte_8.dump
@@ -0,0 +1,10 @@
+|a+0&#ffffff0@7|(*0&#40ffff15| +0&#ffffff0@64
+|b@3|)*0&#40ffff15> +0&#ffffff0@68
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|-+2#0000000&@1| |I|N|S|E|R|T| |-@1| +0&&@44|2|,|8|-|7| @8|A|l@1| 
diff --git a/src/testdir/test_matchparen.vim b/src/testdir/test_matchparen.vim
index 70aa38f..49d3510 100644
--- a/src/testdir/test_matchparen.vim
+++ b/src/testdir/test_matchparen.vim
@@ -108,5 +108,35 @@
   call StopVimInTerminal(buf)
 endfunc
 
+" Test that matchparen works with multibyte chars in 'matchpairs'
+func Test_matchparen_mbyte()
+  CheckScreendump
+
+  let lines =<< trim END
+    source $VIMRUNTIME/plugin/matchparen.vim
+    call setline(1, ['aaaaaaaa(', 'bbbb)cc'])
+    set matchpairs+=(:)
+  END
+
+  call writefile(lines, 'XmatchparenMbyte', 'D')
+  let buf = RunVimInTerminal('-S XmatchparenMbyte', #{rows: 10})
+  call VerifyScreenDump(buf, 'Test_matchparen_mbyte_1', {})
+  call term_sendkeys(buf, "$")
+  call VerifyScreenDump(buf, 'Test_matchparen_mbyte_2', {})
+  call term_sendkeys(buf, "j")
+  call VerifyScreenDump(buf, 'Test_matchparen_mbyte_3', {})
+  call term_sendkeys(buf, "2h")
+  call VerifyScreenDump(buf, 'Test_matchparen_mbyte_4', {})
+  call term_sendkeys(buf, "0")
+  call VerifyScreenDump(buf, 'Test_matchparen_mbyte_5', {})
+  call term_sendkeys(buf, "kA")
+  call VerifyScreenDump(buf, 'Test_matchparen_mbyte_6', {})
+  call term_sendkeys(buf, "\<Down>")
+  call VerifyScreenDump(buf, 'Test_matchparen_mbyte_7', {})
+  call term_sendkeys(buf, "\<C-W>")
+  call VerifyScreenDump(buf, 'Test_matchparen_mbyte_8', {})
+
+  call StopVimInTerminal(buf)
+endfunc
 
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/version.c b/src/version.c
index 9522cc8..f28c66f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    694,
+/**/
     693,
 /**/
     692,