Generate dependency information
The Clang-based `bcc32c.exe` doesn't implement the `-Hp` option, so we
have to use [`cpp32.exe`][1] instead. Therefore, change the dependency-
emitting command to use `$(CPP)` instead of `$(CC)`, which which also
uncovered the [existing bug of `2>&1` before `> $dep`][2]. Also
C++Builder's `make.exe` doesn't implement `2>&1` in its command runner,
so wrap the whole line in a `cmd /C`.
[1]: http://docwiki.embarcadero.com/RADStudio/Sydney/en/CPP32.EXE,_the_C_Compiler_Preprocessor
[2]: https://ss64.com/nt/syntax-redirection.html
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/13540)