Restores the reverted commit, which was reverted due to missing CQ.


Remove ANSI versions of all PI functions and structures.

Rename Unicode PI definitions to unsiffixed form (i.e. strip the final
W),
define -DUNICODE -D_UNICODE in native code to match.

Remove flag=dynamic from functions that are always available on the
target
platform (Vista and later). This is necessary because unsuffixed Unicode
functions can't be dynamic.

Remove redundant OS.IsUnicode variable.


Change-Id: I8fe8a53e9f2c4c3f4cc0a1aa98c2385cc4d19299
Signed-off-by: Nikita Nemkin <nikita@nemkin.ru>