Update tointlmathematicalvalue tests

[romulocintra]

Added tests for Limit exponent of intl mathematical value #98

[sffc]

Thanks, @romulocintra!

[sffc]

This PR currently tests only the Number path. Please also test the String path.

Please test the following inputs (and, for additional coverage, the negative versions of each):

// Values that should *not* overflow to ∞:
Number.MAX_VALUE
String(Number.MAX_VALUE)
Number.MAX_VALUE / 2
String(Number.MAX_VALUE / 2)
1e308
"1e308"
"1" + Array(308).fill("0").join("")
Array(309).fill("1").join("")

// Values that should overflow to ∞:
Number.MAX_VALUE * 2
1e309
"1e309"
"1" + Array(309).fill("0").join("")
Array(310).fill("1").join("")

// Values that should *not* underflow to 0:
// Note: Please set the rounding strategy to maximumSignificantDigits: 10
Number.MIN_VALUE
String(Number.MIN_VALUE)
Number.MIN_VALUE * 2
String(Number.MIN_VALUE * 2)
1e-324
"1e-324"
"1.1111111111111111111e-324" // should round to 10 significant digits
"0." + Array(323).fill("0").join("") + "1"
"0." + Array(323).fill("0").join("") + Array(30).fill("1").join("") // should round to 10 significant digits

// Values that should underflow to zero:
Number.MIN_VALUE / 2
1e-325
"1e-325"
"1.1111111111111111111e-325"
"0." + Array(324).fill("0").join("") + "1"
"0." + Array(324).fill("0").join("") + Array(30).fill("1").join("")