[Fix] `toExponential`: use `thisNumberValue` instead of `Number()`
[Fix] `toExponential`: use `thisNumberValue` instead of `Number()`

See https://github.com/es-shims/es5-shim/commit/5badb9657a343c7620f2fde14316a2e7d934059b#r55784369

es-shims/es5-shim,ljharb/es5-shim,es-shims/es5-shim,ljharb/es5-shim