Fix crash when running on Windows 95.

It looks like CoInitializeEx() is not available on Windows 95. This
commit changes it so that if CoInitializeEx() cannot be found, such as
the case with Windows 95, it falls back to CoInitialize().

As of this commit, a crash still occurs when trying to initialize the
DirectSound backend. The WinMM backend works, however.

miniaudio.h

@@ -7375,6 +7375,7 @@ struct ma_context
         struct
         {
             /*HMODULE*/ ma_handle hOle32DLL;
+            ma_proc CoInitialize;
             ma_proc CoInitializeEx;
             ma_proc CoUninitialize;
             ma_proc CoCreateInstance;
@@ -18097,6 +18098,7 @@ static ma_result ma_result_from_HRESULT(HRESULT hr)
     }
 }
 
+typedef HRESULT (WINAPI * MA_PFN_CoInitialize)(LPVOID pvReserved);
 typedef HRESULT (WINAPI * MA_PFN_CoInitializeEx)(LPVOID pvReserved, DWORD  dwCoInit);
 typedef void    (WINAPI * MA_PFN_CoUninitialize)(void);
 typedef HRESULT (WINAPI * MA_PFN_CoCreateInstance)(REFCLSID rclsid, LPUNKNOWN pUnkOuter, DWORD dwClsContext, REFIID riid, LPVOID *ppv);
@@ -19611,7 +19613,7 @@ WIN32 COMMON
 *******************************************************************************/
 #if defined(MA_WIN32)
 #if defined(MA_WIN32_DESKTOP)
-    #define ma_CoInitializeEx(pContext, pvReserved, dwCoInit)                          ((MA_PFN_CoInitializeEx)pContext->win32.CoInitializeEx)(pvReserved, dwCoInit)
+    #define ma_CoInitializeEx(pContext, pvReserved, dwCoInit)                          ((pContext->win32.CoInitializeEx) ? ((MA_PFN_CoInitializeEx)pContext->win32.CoInitializeEx)(pvReserved, dwCoInit) : ((MA_PFN_CoInitialize)pContext->win32.CoInitialize)(pvReserved))
     #define ma_CoUninitialize(pContext)                                                ((MA_PFN_CoUninitialize)pContext->win32.CoUninitialize)()
     #define ma_CoCreateInstance(pContext, rclsid, pUnkOuter, dwClsContext, riid, ppv)  ((MA_PFN_CoCreateInstance)pContext->win32.CoCreateInstance)(rclsid, pUnkOuter, dwClsContext, riid, ppv)
     #define ma_CoTaskMemFree(pContext, pv)                                             ((MA_PFN_CoTaskMemFree)pContext->win32.CoTaskMemFree)(pv)
@@ -40179,6 +40181,7 @@ static ma_result ma_context_init_backend_apis__win32(ma_context* pContext)
         return MA_FAILED_TO_INIT_BACKEND;
     }
 
+    pContext->win32.CoInitialize     = (ma_proc)ma_dlsym(pContext, pContext->win32.hOle32DLL, "CoInitialize");
     pContext->win32.CoInitializeEx   = (ma_proc)ma_dlsym(pContext, pContext->win32.hOle32DLL, "CoInitializeEx");
     pContext->win32.CoUninitialize   = (ma_proc)ma_dlsym(pContext, pContext->win32.hOle32DLL, "CoUninitialize");
     pContext->win32.CoCreateInstance = (ma_proc)ma_dlsym(pContext, pContext->win32.hOle32DLL, "CoCreateInstance");
@@ -41259,7 +41262,6 @@ MA_API ma_result ma_device_init_ex(const ma_backend backends[], ma_uint32 backen
         allocationCallbacks = ma_allocation_callbacks_init_default();
     }
 
-
     pContext = (ma_context*)ma_malloc(sizeof(*pContext), &allocationCallbacks);
     if (pContext == NULL) {
         return MA_OUT_OF_MEMORY;