random: Fix uwp compilation.

Author: Sibras

random/random-drbg.c

@@ -162,6 +162,7 @@
 #ifdef HAVE_W32_SYSTEM
 # include <process.h>
 # if defined(WINAPI_FAMILY) && (WINAPI_FAMILY==WINAPI_FAMILY_PC_APP || WINAPI_FAMILY==WINAPI_FAMILY_PHONE_APP)
+#  include <windows.h>
 #  define getpid() GetCurrentProcessId()
 # endif
 #endif

random/random.c

@@ -47,6 +47,7 @@
 #ifdef HAVE_W32_SYSTEM
 # include <process.h>
 # if defined(WINAPI_FAMILY) && (WINAPI_FAMILY==WINAPI_FAMILY_PC_APP || WINAPI_FAMILY==WINAPI_FAMILY_PHONE_APP)
+#  include <windows.h>
 #  define getpid() GetCurrentProcessId()
 # endif
 #endif

random/rndw32uwp.cpp

@@ -19,6 +19,7 @@
 #include "config.h"
 #include "types.h"
 #include "g10lib.h"
+#include "windows.h"
 
 using namespace Platform;
 using namespace Windows::Security::Cryptography;