Equality comparison tests for bigint (#1257)

...language/expressions/does-not-equals/bigint-and-bigint.js

...anguage/expressions/does-not-equals/bigint-and-boolean.js

...ions/does-not-equals/bigint-and-incomparable-primitive.js

...uage/expressions/does-not-equals/bigint-and-non-finite.js

...expressions/does-not-equals/bigint-and-number-extremes.js

...language/expressions/does-not-equals/bigint-and-number.js

...language/expressions/does-not-equals/bigint-and-object.js

...language/expressions/does-not-equals/bigint-and-string.js

test/language/expressions/equals/bigint-and-bigint.js

test/language/expressions/equals/bigint-and-boolean.js

...e/expressions/equals/bigint-and-incomparable-primitive.js

test/language/expressions/equals/bigint-and-non-finite.js

...language/expressions/equals/bigint-and-number-extremes.js

test/language/expressions/equals/bigint-and-number.js

test/language/expressions/equals/bigint-and-object.js

test/language/expressions/equals/bigint-and-string.js

...e/expressions/strict-does-not-equals/bigint-and-bigint.js

.../expressions/strict-does-not-equals/bigint-and-boolean.js

...rict-does-not-equals/bigint-and-incomparable-primitive.js

...pressions/strict-does-not-equals/bigint-and-non-finite.js