Help the stack walker to find the location of a throw statement
Avoid multiple traversals of scan bits in marking code, fix bit rot in GC tests.
Rewrite rt_finalize with GC-specific optimizations.
Don't clear the finalize bit twice.
Avoid doing the same bit twiddling multiple times in Gcx.setBits().
Lazily instantiate nointerior, since it's seldom used.
Apply the setBits() tricks to clrBits().
Batch bit clearing in small allocation pool sweep.
Fix a bug in the new batch commit code.
Manually inline a nested function that I realized was making things more complicated, not less.
Fix function prototype.
Add dawgfoto's code review suggestions.
This check is required after all because clear() can wreak havok otherwise.
Commenting out the profiling somehow got stomped on.
temporarily disable failing buggy core.time tests until they're fixed
rename simd() to __simd()
Fixed function overload issue with private abs in core.time.
Moved std.datetime.abs to core.time.

The duration types are in core.time, so it makes the most sense to put
the abs function for them in core.time rather than std.datetime. I
hadn't done that before, because abs for long is in std.math, but it's
not a big deal to reimplement it privately in core.time, and it's now
there for core.time's unit tests anyway.
Change version( Win32 ) to version( Windows ) if Win64 would be supported.
Merge pull request #128 from andralex/master

This adds true ranges for byKey and byValue.