All prebuilt libraries are available in the php-libs repositories

• postgres sources, fetch our patched version or the original sources
• Common tools used to compile PHP
• openssl libs

See the general MSVC build instructions

• create config.pl with $config->{openssl} = 'path\to\deps';
• perl mkvcbuild.pl
• devenv pgsql.sln
• upgrade solution
• copy Debug config to DebugStatic config
• copy Release config to ReleaseStatic config
• fix TargetNames (prepend _a, _debug, _a_debug)
• DebugStatic and ReleaseStatic: fix config type, output and temp folder
• build project 'libpq' for all four configs

cd src\interfaces\libpq
nmake /f win32.mak USE_OPENSSL=1 SSL_INC=<ssl include> SSL_LIB_PATH=<ssl lib>

• for debug add DEBUG=1
• for x64 add CPU=AMD64
• for vc11 (PHP 5.6) builds only, add NOCFG=1

• Download the respective source package from https://www.postgresql.org/ftp/source/
• Replace all files in the repo except README.md and postgresql-*.patch with the downloaded sources
• Apply the existing patch

• cd src\tools\msvc
• run build libpq in x86 and x64 environment (requires Perl), and compare src\include\pg_config.h.win32 with the generated src\include\pg_config.h, and update the former accordingly.