fix warning in mingw gcc (#1286)

src/renderer_d3d11.cpp

@@ -4623,7 +4623,7 @@ BX_PRAGMA_DIAGNOSTIC_POP();
 		deviceCtx->CopyResource(m_texture3d, *_gpuTexture3d);
 
 		D3D11_MAPPED_SUBRESOURCE mappedResource;
-		deviceCtx->Map(m_texture3d, 0, D3D11_MAP_WRITE, NULL, &mappedResource);
+		deviceCtx->Map(m_texture3d, 0, D3D11_MAP_WRITE, 0, &mappedResource);
 		m_descriptor = reinterpret_cast<IntelDirectAccessResourceDescriptor*>(mappedResource.pData);
 
 		return m_descriptor->ptr;

src/renderer_d3d12.cpp

@@ -4966,8 +4966,8 @@ data.NumQualityLevels = 0;
  				box.bottom = blit.m_srcY + height;;
  				box.back   = blit.m_srcZ + bx::uint32_imax(1, depth);
 
-				D3D12_TEXTURE_COPY_LOCATION dstLocation = { dst.m_ptr, D3D12_TEXTURE_COPY_TYPE_SUBRESOURCE_INDEX, {{}} };
-				D3D12_TEXTURE_COPY_LOCATION srcLocation = { src.m_ptr, D3D12_TEXTURE_COPY_TYPE_SUBRESOURCE_INDEX, {{}} };
+				D3D12_TEXTURE_COPY_LOCATION dstLocation = { dst.m_ptr, D3D12_TEXTURE_COPY_TYPE_SUBRESOURCE_INDEX, {{0,{DXGI_FORMAT_UNKNOWN,0,0,0,0}}} };
+				D3D12_TEXTURE_COPY_LOCATION srcLocation = { src.m_ptr, D3D12_TEXTURE_COPY_TYPE_SUBRESOURCE_INDEX, {{0,{DXGI_FORMAT_UNKNOWN,0,0,0,0}}} };
 				m_commandList->CopyTextureRegion(&dstLocation
 					, blit.m_dstX
 					, blit.m_dstY