build, tools, win: add nasm detection for OpenSSL

OpenSSL-1.1.0 requires the nasm assembler for building asm files on
Windows. This finds nasm at \Program Files\NASM\nasm.exe or
\ProgramFiles(x86)\NASM\nasm.exe in vcbuild.bat for users who did not
add its path in their enviroments.

Fixes: https://github.com/nodejs/build/issues/1190
Fixes: https://github.com/nodejs/node/issues/4270
PR-URL: https://github.com/nodejs/node/pull/19794


Reviewed-By: Shigeki Ohtsu <ohtsu@ohtsu.org>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rod Vagg <rod@vagg.org>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>