lib: recover panics within libraries and convert to informative errors

[efd6]

Wrap extensions that could panic with a recover to collect the latest mito/lib line in a stack trace and decorate the error with the failing AST node's ID. Libs that do not have a reasonable potential to panic are not included in this change: crypto, send, strings, time and try.

Example behaviour change with an inserted nil deref to provoke a panic.

    --- FAIL: TestScripts/get (0.27s)
        testscript.go:397: 
            > mito -use http,collections src.cel
            [stderr]
            failed eval: ERROR: <input>:1:4: runtime error: invalid memory address or nil pointer dereference: lib.httpLib.doGet lib/http.go:482
             | get("http://www.example.com/").drop([
             | ...^
            [exit status 1]
            FAIL: testdata/get.txt:1: unexpected command failure

versus the current behaviour

    --- FAIL: TestScripts/get (0.27s)
        testscript.go:397: 
            > mito -use http,collections src.cel
            [stderr]
            failed eval: internal error: runtime error: invalid memory address or nil pointer dereference
            [exit status 1]
            FAIL: testdata/get.txt:1: unexpected command failure

There is no significant impact on performance.

                                           │   old.bench   │              new.bench               │
                                           │    sec/op     │    sec/op     vs base                │
Mito/hello_world_static/unfolded-20           545.6n ±  3%   560.6n ±  5%        ~ (p=0.123 n=10)
Mito/hello_world_static/folded-20             578.3n ±  7%   578.9n ±  6%        ~ (p=0.631 n=10)
Mito/hello_world_object_static/unfolded-20    3.467µ ±  5%   3.513µ ±  3%        ~ (p=0.436 n=10)
Mito/hello_world_object_static/folded-20      3.507µ ±  4%   3.490µ ±  2%        ~ (p=0.529 n=10)
Mito/nested_static/unfolded-20                13.75µ ±  3%   13.80µ ±  4%        ~ (p=0.912 n=10)
Mito/nested_static/folded-20                  13.67µ ±  8%   13.52µ ±  4%        ~ (p=0.529 n=10)
Mito/encode_json_static/unfolded-20           14.28µ ±  6%   14.06µ ±  4%        ~ (p=0.912 n=10)
Mito/encode_json_static/folded-20             1.032µ ±  8%   1.027µ ±  7%        ~ (p=0.853 n=10)
Mito/nested_collate_static/unfolded-20        6.011µ ±  2%   5.888µ ±  4%        ~ (p=0.247 n=10)
Mito/nested_collate_static/folded-20          1.463µ ±  9%   1.500µ ±  3%        ~ (p=0.529 n=10)
Mito/hello_world_state/unfolded-20            649.6n ±  7%   650.6n ±  5%        ~ (p=0.912 n=10)
Mito/hello_world_state/folded-20              638.9n ±  4%   648.3n ±  6%        ~ (p=0.912 n=10)
Mito/hello_world_object_state/unfolded-20     3.699µ ±  6%   3.708µ ±  4%        ~ (p=0.853 n=10)
Mito/hello_world_object_state/folded-20       3.570µ ±  6%   3.716µ ±  3%   +4.12% (p=0.005 n=10)
Mito/nested_state/unfolded-20                 11.23µ ±  4%   11.40µ ±  4%        ~ (p=0.516 n=10)
Mito/nested_state/folded-20                   11.13µ ±  5%   11.29µ ±  4%        ~ (p=0.579 n=10)
Mito/encode_json_state/unfolded-20            3.122µ ±  4%   3.143µ ±  7%        ~ (p=0.813 n=10)
Mito/encode_json_state/folded-20              3.128µ ±  3%   3.211µ ±  7%        ~ (p=0.247 n=10)
Mito/nested_collate_list_state/unfolded-20    13.45µ ±  7%   13.34µ ±  4%        ~ (p=0.393 n=10)
Mito/nested_collate_list_state/folded-20      13.39µ ±  7%   13.90µ ±  5%        ~ (p=0.190 n=10)
Mito/nested_collate_map_state/unfolded-20     14.68µ ±  6%   14.45µ ±  7%        ~ (p=0.796 n=10)
Mito/nested_collate_map_state/folded-20       13.78µ ± 10%   14.79µ ±  6%        ~ (p=0.075 n=10)
Mito/null_net/unfolded-20                     74.31µ ±  9%   72.99µ ± 12%        ~ (p=0.481 n=10)
Mito/null_net/folded-20                       478.5n ±  8%   471.3n ±  6%        ~ (p=0.315 n=10)
Mito/hello_world_net/unfolded-20              94.35µ ± 14%   93.67µ ± 12%        ~ (p=0.280 n=10)
Mito/hello_world_net/folded-20                621.2n ±  5%   643.8n ±  5%        ~ (p=0.052 n=10)
Mito/hello_world_object_net/unfolded-20       113.2µ ± 10%   109.3µ ± 15%        ~ (p=0.684 n=10)
Mito/hello_world_object_net/folded-20         3.944µ ±  5%   3.872µ ±  3%        ~ (p=0.280 n=10)
Mito/nested_net/unfolded-20                   146.5µ ± 10%   146.4µ ±  8%        ~ (p=0.529 n=10)
Mito/nested_net/folded-20                    15.707µ ±  4%   8.616µ ± 69%  -45.15% (p=0.000 n=10)
Mito/encode_json_null_net/unfolded-20         96.87µ ± 11%   96.10µ ±  8%        ~ (p=0.971 n=10)
Mito/encode_json_null_net/folded-20           1.287µ ±  5%   1.287µ ±  7%        ~ (p=0.617 n=10)
Mito/encode_json_net/unfolded-20              112.5µ ± 41%   121.8µ ±  4%        ~ (p=0.063 n=10)
Mito/encode_json_net/folded-20                1.099µ ±  8%   1.101µ ±  8%        ~ (p=1.000 n=10)
Mito/nested_collate_list_net/unfolded-20      147.3µ ±  7%   150.2µ ±  7%        ~ (p=0.218 n=10)
Mito/nested_collate_list_net/folded-20        1.678µ ±  5%   1.661µ ±  2%        ~ (p=0.225 n=10)
Mito/nested_collate_map_net/unfolded-20       152.4µ ±  6%   164.1µ ±  7%   +7.68% (p=0.023 n=10)
Mito/nested_collate_map_net/folded-20         1.644µ ±  5%   1.734µ ±  8%        ~ (p=0.063 n=10)
geomean                                       6.813µ         6.772µ         -0.60%

[andrewkroh]

LGTM