Fix Accessors panics

[HalidOdat]

It changes the following:

• Accessors now return undefined.

[github-actions]

Test262 conformance changes:

Test result	master count	PR count	difference
Total	78,413	78,413	0
Passed	18,189	18,375	+186
Ignored	15,507	15,507	0
Failed	44,717	44,531	-186
Panics	13,519	12,260	-1,259
Conformance	23.20	23.43	+0.24%

[codecov]

Codecov Report

Merging #902 into master will decrease coverage by 0.02%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master     #902      +/-   ##
==========================================
- Coverage   59.44%   59.41%   -0.03%     
==========================================
  Files         166      166              
  Lines       10474    10477       +3     
==========================================
- Hits         6226     6225       -1     
- Misses       4248     4252       +4     

Impacted Files	Coverage Δ
boa/src/object/internal_methods.rs	57.14% <0.00%> (-0.83%)	⬇️
boa/src/value/mod.rs	74.10% <0.00%> (-0.49%)	⬇️

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[github-actions]

Benchmark for cad9698

Click to view benchmark

Test	PR Benchmark	Master Benchmark	%
Arithmetic operations (Execution)	436.6±18.23ns	354.9±26.96ns	+23.02%
Arithmetic operations (Full)	285.6±10.22µs	257.5±20.07µs	+10.91%
Array access (Execution)	9.5±0.43µs	8.8±0.66µs	+7.95%
Array access (Full)	316.2±26.24µs	275.2±14.06µs	+14.90%
Array creation (Execution)	2.7±0.19ms	2.8±0.18ms	-3.57%
Array creation (Full)	3.3±0.15ms	2.9±0.24ms	+13.79%
Array pop (Execution)	1093.9±45.80µs	1012.9±58.75µs	+8.00%
Array pop (Full)	1594.1±54.20µs	1475.3±84.00µs	+8.05%
Boolean Object Access (Execution)	5.3±0.22µs	4.6±0.28µs	+15.22%
Boolean Object Access (Full)	316.0±20.91µs	277.8±21.39µs	+13.75%
Clean js (Execution)	811.1±38.30µs	708.5±62.58µs	+14.48%
Clean js (Full)	1192.3±89.50µs	992.4±60.31µs	+20.14%
Clean js (Parser)	42.8±1.44µs	40.0±3.29µs	+7.00%
Create Realm	520.8±31.50ns	485.6±35.38ns	+7.25%
Dynamic Object Property Access (Execution)	6.2±0.46µs	5.9±0.35µs	+5.08%
Dynamic Object Property Access (Full)	302.2±11.37µs	278.1±18.56µs	+8.67%
Expression (Parser)	8.1±0.54µs	6.8±0.49µs	+19.12%
Fibonacci (Execution)	1031.8±90.29µs	951.9±57.04µs	+8.39%
Fibonacci (Full)	1300.2±78.80µs	1229.4±75.33µs	+5.76%
For loop (Execution)	25.9±2.49µs	26.3±2.94µs	-1.52%
For loop (Full)	327.7±15.44µs	292.7±17.26µs	+11.96%
For loop (Parser)	19.2±1.40µs	19.0±1.55µs	+1.05%
Goal Symbols (Parser)	14.2±1.06µs	12.6±0.71µs	+12.70%
Hello World (Parser)	3.8±0.16µs	3.4±0.24µs	+11.76%
Long file (Parser)	890.2±76.54ns	785.5±67.87ns	+13.33%
Mini js (Execution)	686.3±57.55µs	628.8±41.18µs	+9.14%
Mini js (Full)	1017.0±60.32µs	908.6±61.70µs	+11.93%
Mini js (Parser)	36.8±2.53µs	34.4±1.89µs	+6.98%
Number Object Access (Execution)	4.3±0.22µs	3.5±0.24µs	+22.86%
Number Object Access (Full)	298.6±16.40µs	265.2±18.48µs	+12.59%
Object Creation (Execution)	6.1±0.62µs	5.2±0.32µs	+17.31%
Object Creation (Full)	314.0±19.31µs	275.6±14.41µs	+13.93%
RegExp (Execution)	11.0±0.51µs	9.9±0.97µs	+11.11%
RegExp (Full)	309.1±14.10µs	271.4±16.22µs	+13.89%
RegExp Literal (Execution)	11.7±0.86µs	11.0±0.94µs	+6.36%
RegExp Literal (Full)	313.0±11.18µs	272.8±16.22µs	+14.74%
RegExp Literal Creation (Execution)	10.9±0.42µs	9.4±0.60µs	+15.96%
RegExp Literal Creation (Full)	284.7±24.88µs	291.1±47.40µs	-2.20%
Static Object Property Access (Execution)	5.9±0.40µs	5.6±0.27µs	+5.36%
Static Object Property Access (Full)	301.8±10.81µs	268.2±16.71µs	+12.53%
String Object Access (Execution)	7.9±0.34µs	7.1±0.42µs	+11.27%
String Object Access (Full)	305.4±13.80µs	268.7±21.28µs	+13.66%
String comparison (Execution)	7.0±0.43µs	6.8±0.60µs	+2.94%
String comparison (Full)	308.6±18.60µs	269.3±16.93µs	+14.59%
String concatenation (Execution)	6.3±0.27µs	5.5±0.33µs	+14.55%
String concatenation (Full)	300.2±17.95µs	275.1±21.05µs	+9.12%
String copy (Execution)	4.8±0.25µs	4.2±0.59µs	+14.29%
String copy (Full)	292.0±25.12µs	267.7±21.77µs	+9.08%
Symbols (Execution)	4.1±0.32µs	4.1±0.34µs	0.00%
Symbols (Full)	284.1±16.67µs	254.2±15.66µs	+11.76%

[Razican]

Thanks! Removing the panics should improve our conformance, and at at least we don't bring down the process executing the interpreter. Looks good to me, I'm a bit intrigued by the benchmarks, but I hope it's just statistical anomalies.

[HalidOdat]

Looks good to me, I'm a bit intrigued by the benchmarks, but I hope it's just statistical anomalies.

That is very strange. You are right, it's probably a statistical anomaly since there is a performance regression in parse/lex benchmarks, I haven't changed anything in the parser/lexer.

[Razican]

Cool, let's merge then :D