Moved from the deprecated "flat" sbt project definition style to the
recommended "multi-project" style.

Bumped dependency versions.

This will fix the problem that some memory is reclaimed by the GC before
the intended end-of-life. Now many classes implement the AutoCloseable
interface and manage their resources in the C++ style.

The normal destination may use the results of the instruction. So the
excClause needs to be created after the instruction is created and the
results are created.

Need testing...

mar.py as a importable function

Put the functionality of mar.py as a importable function that can be used in RPython compiling tool chain.

See merge request !1

Moved CanBeIntegerized to its own package.

Removed "Word" from TypeSizes and uniformly import from uvm.refimpl.

Lifted xxxEntity outside match.

Fixed a bug in MemorySupport.cmpXchgEntity

TODO: Implement the new IR builder.