Speed up the code a little, and stop swapping stream buffers around in case that's the cause of some test failures.

[SVN r58789]

libs/regex

@@ -1 +1 @@
-Subproject commit 0e1e9804dab4a247a933bb1ebd393e7d5a596f54
+Subproject commit 4a826c1ade57e51999d2bd64abb9cf8027c9ccfb