win32: fix compiling unit tests after adding secure LWIP_RAND

ports/win32/include/arch/cc.h

@@ -82,8 +82,10 @@ typedef int sys_prot_t;
 #define strdup   _strdup
 #endif
 
+#ifndef LWIP_NORAND
 extern unsigned int sys_win_rand(void);
 #define LWIP_RAND() (sys_win_rand())
+#endif
 
 #define PPP_INCLUDE_SETTINGS_HEADER
 

ports/win32/msvc/lwIP.vcxproj

@@ -123,7 +123,7 @@
     <ClCompile>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..\..\..\lwip\test\unit;..\..\..\..\lwip\src\include;..\..\..\..\lwip\src\include\ipv4;..\..\..\..\lwip\src\include\ipv6;..\include;..;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>_LIB;WIN32;_DEBUG;LWIP_DEBUG;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>LWIP_NORAND;_LIB;WIN32;_DEBUG;LWIP_DEBUG;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
       <PrecompiledHeader>
@@ -148,7 +148,7 @@
       <Optimization>MaxSpeed</Optimization>
       <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
       <AdditionalIncludeDirectories>..\..\..\..\lwip\test\unit;..\..\..\..\lwip\src\include;..\..\..\..\lwip\src\include\ipv4;..\..\..\..\lwip\src\include\ipv6;..\include;..;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>WIN32;NDEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>LWIP_NORAND;WIN32;NDEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <StringPooling>true</StringPooling>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
       <FunctionLevelLinking>true</FunctionLevelLinking>