Win32: OpenSSL compilation for x64 targets with MSVC. To ensure proper target selection the NGX_MACHINE variable is now set based on the MSVC compiler output, and the OpenSSL target is set based on it. This is not important as long as "no-asm" is used (as in misc/GNUmakefile and win32 build instructions), but might be beneficial if someone is trying to build OpenSSL with assembler code.