Get `gn gen` to succeed on Windows

third_party/sqlite/separate_cache_pool.patch

+diff --git src/pcache1.c src/pcache1.c
+index ad44395..e4d0705 100644
+--- src/pcache1.c
++++ src/pcache1.c
+@@ -549,10 +549,12 @@ static sqlite3_pcache *pcache1Create(int szPage, int bPurgeable){
+   int sz;               /* Bytes of memory required to allocate the new cache */
+ 
+   /*
+-  ** The seperateCache variable is true if each PCache has its own private
++  ** The separateCache variable is true if each PCache has its own private
+   ** PGroup.  In other words, separateCache is true for mode (1) where no
+   ** mutexing is required.
+   **
++  **   *  Always use separate caches (mode-1) if SQLITE_SEPARATE_CACHE_POOLS
++  **
+   **   *  Always use a unified cache (mode-2) if ENABLE_MEMORY_MANAGEMENT
+   **
+   **   *  Always use a unified cache in single-threaded applications
+@@ -560,7 +562,9 @@ static sqlite3_pcache *pcache1Create(int szPage, int bPurgeable){
+   **   *  Otherwise (if multi-threaded and ENABLE_MEMORY_MANAGEMENT is off)
+   **      use separate caches (mode-1)
+   */
+-#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) || SQLITE_THREADSAFE==0
++#ifdef SQLITE_SEPARATE_CACHE_POOLS
++  const int separateCache = 1;
++#elif defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) || SQLITE_THREADSAFE==0
+   const int separateCache = 0;
+ #else
+   int separateCache = sqlite3GlobalConfig.bCoreMutex>0;