Reserving various symbols that appear in darwin
Merge pull request #722 from benharsh/reserve-darwin

Reserving various symbols that appear on darwin

This patch should fix the darwin compilation errors for compSampler*. 'fls' is the name of a function in darwin, and should become a reserved word in Chapel to avoid compilation errors.

These changes should also fix parallel/sync/diten/userLevelEndCount . The 'wait' function can conflict with darwin functions (wait2/3/4) during C compilation.