libs/port: Add support for amd64-mingw32msvc platform.
diff --git a/libs/port/getpagesize.c b/libs/port/getpagesize.c
index 79c2306..0271e5d 100644
--- a/libs/port/getpagesize.c
+++ b/libs/port/getpagesize.c
@@ -30,7 +30,7 @@
 {
 # ifdef __svr4__
     return sysconf(_SC_PAGESIZE);
-# elif defined(__i386__)
+# elif defined(__i386__) || defined(__x86_64__)
     return 4096;
 # else
 #  error Cannot get the page size on this platform