Add more test cases in Double.Test.js to cover floating points

[Devika-Tantry]

Add test cases in Double.Test.js such as the conversion of different normal floating-point values such as "-3.5, -2.1, 2.1, 3.5" to make sure the rounding behavior is FE_TONEAREST and ensure the default conversion behavior does not get affected with compiler upgrades.
Add those test cases in the G test suite in ASW side too. Track this separately there.