* Use the "nearly divisionless" algorithm on all targets.
We have multipliedFullWidth available everywhere now, so we don't need to carry around the old implementation on 32b targets.
Also adds a few more benchmarks for random number generation.
* Obscure the range boundaries for some of the new random value benchmarks.
When these are visible compile-time constants, the compiler is smart enough to evaluate the division in the "nearly divisionless" algorithm, which makes it completely divisionless. That's good, but it obscures what the runtime performance of the algorithm will be when the bounds are _not_ available as compile-time constants. Thus, for some of the newly-added benchmarks, we pass the upper bound through `identity` to hide it from the optimizer (this is imperfect, but it's the simplest tool we have).
We don't want to do this for all the tests for two reasons:
- compile-time constant bounds are a common case that should still be reflected in our testing
- we don't want to perturb existing benchmark results more than we have to.
Values returned by random APIs depend on the bitWidth of the underlying integer type; make sure we use a consistent integer width when expecting particular results.
* Use the `__has_include` and `GRND_RANDOM` macros
* Use `getentropy` instead of `getrandom`
* Use `std::min` from the <algorithm> header
* Move `#if` out of the `_stdlib_random` function
* Use `getrandom` with "/dev/urandom" fallback
* Use `#pragma comment` to import "Bcrypt.lib"
* <https://docs.microsoft.com/en-us/cpp/preprocessor/comment-c-cpp>
* <https://clang.llvm.org/docs/UsersManual.html#microsoft-extensions>
* Use "/dev/urandom" instead of `SecRandomCopyBytes`
* Use `swift::StaticMutex` for shared "/dev/urandom"
* Add `getrandom_available`; use `O_CLOEXEC` flag
Add platform impl docs
Update copyrights
Fix docs
Add _stdlib_random test
Update _stdlib_random test
Add missing &
Notice about _stdlib_random
Fix docs
Guard on upperBound = 0
Test full range of 8 bit integers
Remove some gyb
Clean up integerRangeTest
Remove FixedWidthInteger constraint
Use arc4random universally
Fix randomElement
Constrain shuffle to RandomAccessCollection
warning instead of error
Move Apple's implementation
Fix failing test on 32 bit systems
* [stdlib] Revise documentation for new random APIs
* [stdlib] Fix constraints on random integer generation
* [test] Isolate failing Random test
* [benchmark] Add benchmarks for new random APIs
Fix Float80 test
Value type generators
random -> randomElement
Fix some docs
One more doc fix
Doc fixes & bool fix
Use computed over explicit
