Merge pull request #1224 from thejoshwolfe/bigint-asuintn

harness/typeCoercion.js

test/built-ins/BigInt/asIntN/bigint-tobigint.js

test/built-ins/BigInt/asIntN/bits-toindex.js

test/built-ins/BigInt/asUintN/arithmetic.js

test/built-ins/BigInt/asUintN/asUintN.js

test/built-ins/BigInt/asUintN/bigint-tobigint.js

test/built-ins/BigInt/asUintN/bits-toindex.js

test/built-ins/BigInt/asUintN/length.js

test/built-ins/BigInt/asUintN/name.js

test/built-ins/BigInt/asUintN/order-of-steps.js