typeCoercion.js includes BigInt literal without "features: [BigInt]"

[Constellation]

New typeCoercion.js includes BigInt literal like 0n. And it causes some test failures like test262/test/built-ins/String/prototype/indexOf/position-tointeger.js if VM does not support BigInt literal.
But test262/test/built-ins/String/prototype/indexOf/position-tointeger.js is essentially unrelated to BigInt.

Since BigInt is new feature, and since typeCoercion.js is not marked with features: [BigInt], BigInt(0) is better way.

[leobalter]

Harness files are not required to contain any frontmatter, and for that we don't expect runners to parse harness files for features tags, those should be used on the tests files including them, as the one you mentioned has the features tag for BigInt, already.

The features.yml includes features requirements for includes. Our built-in linter tool will confirm every test including typeCoercion.js has the features BigInt included.

We might need to revisit this, but for now this is the best we have.