Fix rdmd by picking import adjustment from upstream master

PKGBUILD

@@ -2,7 +2,7 @@
 
 pkgname=('dtools')
 pkgver=2.071.0
-pkgrel=1
+pkgrel=2
 pkgdesc="Ancilliary tools for the D programming language"
 license=("custom")
 groups=('dlang')
@@ -20,6 +20,12 @@ sha1sums=('SKIP'
           '3cba29011be2b9d59f6204d6fa0a386b1b2dbd90'
           '7fb5bd71d6c4e90c0ca49b292454e11169afdee8')
 
+prepare()
+{
+    # rdmd is broken without https://github.com/dlang/tools/pull/185
+    sed -i 's|std.syserror|std.windows.syserror|g' $srcdir/tools/rdmd.d
+}
+
 build()
 {
     # DMD=`$srcdir/Arch-PKGBUILDs/d-compiler.sh`