Per the code comment, stdint.h is provided by clang and therefore
conflicts with Glibc; additionally, clang defines some particular
type macros for making the appropriate `typedef`s.
OpenBSD uses clang-10, so we can also use these types on this platform.
This also addresses a test case that has gone awry.
The SwiftStdint.h header is used in the compiler as well. The compiler may be
built with cl (Visual Studio) on Windows, which does not define
`__INTPTR_TYPE__` nor does it define `__INTPTR_WIDTH__`. Simply define the
`__swift_{,u}intptr_t` typedefs as Microsoft does on that platform when building
with Visual Studio.
The standard library has grown significantly, and we need a new
directory structure that clearly reflects the role of the APIs, and
allows future growth.
See stdlib/{public,internal,private}/README.txt for more information.
Swift SVN r25876
