Update Math functions to handle distinct -0 and +0

test/built-ins/Math/abs/S15.8.2.1_A2.js

test/built-ins/Math/acos/S15.8.2.2_A4.js

test/built-ins/Math/asin/S15.8.2.3_A4.js

test/built-ins/Math/asin/S15.8.2.3_A5.js

test/built-ins/Math/atan/S15.8.2.4_A2.js

test/built-ins/Math/atan/S15.8.2.4_A3.js

test/built-ins/Math/atan2/S15.8.2.5_A14.js

test/built-ins/Math/atan2/S15.8.2.5_A16.js

test/built-ins/Math/atan2/S15.8.2.5_A4.js

test/built-ins/Math/atan2/S15.8.2.5_A5.js

test/built-ins/Math/atan2/S15.8.2.5_A8.js

test/built-ins/Math/atan2/S15.8.2.5_A9.js

test/built-ins/Math/ceil/S15.8.2.6_A2.js

test/built-ins/Math/ceil/S15.8.2.6_A3.js

test/built-ins/Math/ceil/S15.8.2.6_A6.js

test/built-ins/Math/exp/S15.8.2.8_A5.js

test/built-ins/Math/floor/S15.8.2.9_A2.js

test/built-ins/Math/floor/S15.8.2.9_A3.js

test/built-ins/Math/floor/S15.8.2.9_A6.js

test/built-ins/Math/log/S15.8.2.10_A4.js