Allow DX11 renderer to be used with devices with lower feature levels.

examples/directx11_example/imgui_impl_dx11.cpp

@@ -323,7 +323,7 @@ bool    ImGui_ImplDX11_CreateDeviceObjects()
             return output;\
             }";
 
-        D3DCompile(vertexShader, strlen(vertexShader), NULL, NULL, NULL, "main", "vs_5_0", 0, 0, &g_pVertexShaderBlob, NULL);
+        D3DCompile(vertexShader, strlen(vertexShader), NULL, NULL, NULL, "main", "vs_4_0", 0, 0, &g_pVertexShaderBlob, NULL);
         if (g_pVertexShaderBlob == NULL) // NB: Pass ID3D10Blob* pErrorBlob to D3DCompile() to get error showing in (const char*)pErrorBlob->GetBufferPointer(). Make sure to Release() the blob!
             return false;
         if (g_pd3dDevice->CreateVertexShader((DWORD*)g_pVertexShaderBlob->GetBufferPointer(), g_pVertexShaderBlob->GetBufferSize(), NULL, &g_pVertexShader) != S_OK)
@@ -369,7 +369,7 @@ bool    ImGui_ImplDX11_CreateDeviceObjects()
             return out_col; \
             }";
 
-        D3DCompile(pixelShader, strlen(pixelShader), NULL, NULL, NULL, "main", "ps_5_0", 0, 0, &g_pPixelShaderBlob, NULL);
+        D3DCompile(pixelShader, strlen(pixelShader), NULL, NULL, NULL, "main", "ps_4_0", 0, 0, &g_pPixelShaderBlob, NULL);
         if (g_pPixelShaderBlob == NULL)  // NB: Pass ID3D10Blob* pErrorBlob to D3DCompile() to get error showing in (const char*)pErrorBlob->GetBufferPointer(). Make sure to Release() the blob!
             return false;
         if (g_pd3dDevice->CreatePixelShader((DWORD*)g_pPixelShaderBlob->GetBufferPointer(), g_pPixelShaderBlob->GetBufferSize(), NULL, &g_pPixelShader) != S_OK)