The data emitted by `DebugDescriptionMacro` is constant. For that reason, it was placed
in `__DATA_CONST`. However, this causes a problem with the linker, which emits an error
if the `__DATA_CONST` segment is _not_ marked `SG_READ_ONLY`.
After discussion, it was pointed out that if the constant data has no fixups, then it
can and should be in the the `__TEXT` segment. The `__DATA_CONST` segment is for data
that is essentially constant but contains dyld fixups.
Fixes the way `DebugDescriptionMacro` produces a regex type name.
The problem was use of backslash escapes that weren't sufficiently escaped. They needed
to be double escaped. To avoid this trap, the regexes now use `[.]` to match a dot,
instead of the more conventional `\.` syntax.
