required by UQ-PAC/aslp#92

* extract arm environment into separate file.

* allow loading files from either disk or memory

* use ppx_blob to embed ASL files instead of dune-site

This is instead of installing the ASL files to disk.
This should make the installation less liable to random
breakages when installed or linked in an unexpected way.

The binary size increases by 6MB.

Updates tests/coverage/run.sh to substitute away the
new file paths of the embedded files, so no coverage
re-generation needed.

* replace --aarch64-dir with --export-aarch64

this is more useful once the MRA files are bundled.

* extract arm environment into separate file.

* allow loading files from either disk or memory

* use ppx_blob to embed ASL files instead of dune-site

This is instead of installing the ASL files to disk.
This should make the installation less liable to random
breakages when installed or linked in an unexpected way.

The binary size increases by 6MB.

Updates tests/coverage/run.sh to substitute away the
new file paths of the embedded files, so no coverage
re-generation needed.

* replace --aarch64-dir with --export-aarch64

this is more useful once the MRA files are bundled.

* Split libASL and isolate Z3 into virtual library (#91)

Z3 links to a native shared library, and so is unsuitable for use via js-of-ocaml. This separates the one use of Z3 in the code (the type-checker's constraint solver) into a separate library which may be stubbed for non-native platforms.

This separates libASL into two parts: libASL_ast which is the minimum needed to define the ASL syntax tree, and libASL which contains the rest of the library. libASL should still be used as the public interface of the library. Since libASL re-exports all of libASL_ast, this should not affect the API visible by downstream users.

This is required since we need to insert a platform-specific library, libASL_support, which introduces z3 only on native builds. The dependency tree now looks like: libASL_ast <- libASL_support (virtual) <- libASL.

* remove pcre library, use ocaml str instead (#93)

PCRE relies on a shared library, precluding its use in Javascript.
instead, we use the standard ocaml "str" library. note, however,
that this supports a smaller subscript of regex (notably no negative
lookahead), and has a different syntax.

see: https://ocaml.org/manual/5.2/api/Str.html

* Embed ARM ASL specs within OCaml (#92)

* extract arm environment into separate file.

* allow loading files from either disk or memory

* use ppx_blob to embed ASL files instead of dune-site

This is instead of installing the ASL files to disk.
This should make the installation less liable to random
breakages when installed or linked in an unexpected way.

The binary size increases by 6MB.

Updates tests/coverage/run.sh to substitute away the
new file paths of the embedded files, so no coverage
re-generation needed.

* replace --aarch64-dir with --export-aarch64

this is more useful once the MRA files are bundled.

* initialising jsoo

* tcheck: make global env0 mutable

necessary for correct unmarshalling, as this
must contain global variables

* dummy libASL to reduce conflicts

* rename libASL parts to stage0/stage1