Implement basic Quilc C API

[kartik-s]

This PR resolves #788, providing a way to build a small subset of Quilc functionality into a shared library.

Notes

• Tested on macOS, but not Linux.
• The Makefile for the C tests includes a condition to add the -pagezero_size 0x100000 compilation option when compiling on macOS to address the issue at the bottom of the sbcl-librarian README.
• The Python tests will not run on macOS unless either 1) you are using a custom build of SBCL that negates the aforementioned page zero size issue or 2) you are using a custom build of Python that was compiled with the -pagezero_size 0x100000 option.
• The test-build-lib test that builds libquilc.dylib will fail unless you have libsbcl.so in your library path. Instructions:

1. Go to your SBCL source directory.
2. Run sh make-shared-library.sh.
3. Copy src/runtime/libsbcl.so into your library path, e.g. /usr/local/lib/.

Functions

Parsing/printing

• [x] quilc_parse_quil
• [x] quilc_print_program

Chip specifications

• [x] quilc_build_nq_linear_chip
• [x] quilc_chip_spec_from_isa_descriptor
• [x] quilc_print_chip_spec

Compilation

• [x] quilc_compile_quil
• [x] quilc_compile_protoquil

Testing

• [x] Write tests

[kartik-s]

Need quil-lang/sbcl-librarian#13 to be resolved to fix up C function names.

[notmgsk]

<3