Fixes to compile with dmd 2.066

With the latest dmd 2.066 it was not compiling without this modifications.
Looking again at the code you are right.

And also when I tried the document example for regex it do not match anything and give several warnings for math/double modules.
-----
import tango.io.Stdout;
import tango.text.Regex;

void main()
{
    foreach(m; Regex("ab").search("qwerabcabcababqwer"))
        Stdout.formatln("{}[{}]{}", m.pre, m.match(0), m.post);
}
----
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/stdc/math.d(436): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!>'
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/stdc/math.d(437): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!>'
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/stdc/math.d(438): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!>'
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/stdc/math.d(441): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!>='
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/stdc/math.d(442): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!>='
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/stdc/math.d(443): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!>='
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/stdc/math.d(446): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!<'
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/stdc/math.d(447): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!<'
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/stdc/math.d(448): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!<'
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/stdc/math.d(451): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!<='
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/stdc/math.d(452): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!<='
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/stdc/math.d(453): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!<='
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/stdc/math.d(456): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!<>'
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/stdc/math.d(457): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!<>'
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/stdc/math.d(458): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!<>'
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/math/IEEE.d(858): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!<='
/home/mingo/dev/d/src/install/bin/../../Tango-D2/tango/math/IEEE.d(1403): Warning: use std.math.isNaN to deal with NaN operands rather than floating point operator '!<'
---