Improve equal operations.

[zherczeg]

The code is simplified a lot (a lot of code is deleted).

[LaszloLango]

Please measure the PR on RPi2.

[zherczeg]

Since equal is not a frequent operation, the difference is not big. Although it slightly improved the perf in 12 cases.

Benchmark	Perf (sec)
3d-cube.js	1.490 -> 1.491 : -0.068%
3d-raytrace.js	1.539 -> 1.531 : +0.524%
access-binary-trees.js	0.763 -> 0.754 : +1.205%
access-fannkuch.js	3.253 -> 3.127 : +3.873%
access-nbody.js	1.589 -> 1.561 : +1.736%
bitops-3bit-bits-in-byte.js	0.793 -> 0.796 : -0.473%
bitops-bits-in-byte.js	1.043 -> 1.045 : -0.279%
bitops-bitwise-and.js	1.945 -> 1.907 : +1.959%
bitops-nsieve-bits.js	2.559 -> 2.525 : +1.340%
controlflow-recursive.js	0.548 -> 0.558 : -1.713%
crypto-aes.js	1.480 -> 1.456 : +1.635%
crypto-md5.js	0.929 -> 0.926 : +0.256%
crypto-sha1.js	0.872 -> 0.876 : -0.445%
date-format-tofte.js	1.173 -> 1.151 : +1.897%
date-format-xparb.js	0.612 -> 0.594 : +2.904%
math-cordic.js	2.000 -> 2.010 : -0.520%
math-partial-sums.js	1.124 -> 1.106 : +1.535%
math-spectral-norm.js	0.888 -> 0.897 : -0.966%
string-base64.js	4.736 -> 4.691 : +0.945%
string-fasta.js	2.267 -> 2.254 : +0.588%
Geometric mean:	+0.806%

Binary sizes (bytes)
old:167192
new:166872

However, the binary size is decreased by 300 bytes, which is useful.

[LaszloLango]

Could you also fix comments in the touched functions? (// -> /* */)

[LaszloLango]

LGTM

[dbatyai]

This should be above ecma-conversion.h

[dbatyai]

LGTM after the include is fixed