Instead of calling a function with two uint32_t parameters, pass a MemoryElement structure that has named and documented fields.

This structure includes the Type field, which will be used by the debugger for knowing how to interpret the value.

Bug: b/145351270
Change-Id: I21e86b9ba117bcde21150b408d8a7552729203e2
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/38911
Presubmit-Ready: Ben Clayton <bclayton@google.com>
Tested-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>