workaround prime cases of issue 10985 in std.regex
Fix issue 4673
Remove modules crc32 and std.md5 which had been deprecated by 6ff6adc5bf7d13b33e27985c53377cd20d7648e6
@blackwhale's review revealed that among rox
typo
Merge pull request #1207 from andralex/4673

Fix issue 4673 - Bug in std.string (isNumeric)
Merge pull request #1814 from CyberShadow/std-stdio-flock

std.stdio: Add file locking functions
Merge pull request #1553 from blackwhale/force-inline-regex

Some simple std.regex optimization
add lref links to std.datetime
Merge pull request #1816 from WalterBright/lref-links

add lref links to std.datetime
fix Issue 11831 - std.zip no longer allows setting madeVersion field

- add deprecated ref accessor
Merge pull request #1815 from Geod24/remove-deprecated-modules

Remove deprecated crc32 and std.md5 [Again]
Merge pull request #1817 from MartinNowak/fix11831

fix Issue 11831 - std.zip no longer allows setting madeVersion field
std.file: Fix race condition when mkdirRecurse runs concurrently

mkdirRecurse would crash if a directory was created between its
exists() and mkdir() calls. This could occur if mkdirRecurse was called
at the same time from mutiple threads or processes.

Instead of relying on the exists() check to indicate whether the next
mkdir() should succeed, we explicitly ignore "already exists" errors
from the OS. Note that this changes the behavior of mkdirRecurse when
the leaf directory already existed: previously it would throw, whereas
now it will silently succeed. The new behavior is conformant with some
other implementations of "recursive mkdir": the -p flag of the GNU
tool, Ruby's mkpath, Java's mkdirs, and Perl's make_path. (On the
other hand, the old behavior was equivalent to the behavior of
Python's makedirs).
std.file: Simplify/optimize mkdirRecurse

The left.length != pathname.length check both takes care of the
Windows-only check, and it avoids a pointless stat on the FS root.