Fixes most warnings using the Visual Studio C++ 64 bit compiler.
Should be noop

Bug b/132445520

Change-Id: I7844062244478b39299729cf4e4c0b647e2f5b14
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/31150Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>