Implement realm object and support realms for built-ins and JS functions

[zherczeg]

• Type for realm objects is introduced (ecma_global_object_t)
• Realm reference is added to built-in objects and ECMAScript functions
• Resolving built-ins, global environments, and scopes require realm object
• Unnecessary global object accesses are removed from the code

Missing: external functions and static snapshot functions have no realm reference

[zherczeg]

Depends on #4352

[zherczeg]

Benchmark	Heap (bytes)	Stack (bytes)	Perf (sec)
3d-cube.js	10680 -> 11200 : -4.869%	13672 -> 14056 : -2.809%	1.145 -> 1.149 : -0.307%
3d-morph.js	289008 -> 289224 : -0.075%	1712 -> 1704 : +0.467%	1.194 -> 1.187 : +0.572%
3d-raytrace.js	119384 -> 117648 : +1.454%	2548 -> 2596 : -1.884%	1.329 -> 1.359 : -2.298%
access-binary-trees.js	27120 -> 28656 : -5.664%	3376 -> 3448 : -2.133%	0.769 -> 0.774 : -0.661%
access-fannkuch.js	1584 -> 1784 : -12.626%	1784 -> 1776 : +0.448%	2.559 -> 2.552 : +0.273%
access-nbody.js	4088 -> 4600 : -12.524%	1872 -> 1864 : +0.427%	1.577 -> 1.570 : +0.483%
bitops-3bit-bits-in-byte.js	808 -> 1016 : -25.743%	1728 -> 1720 : +0.463%	0.696 -> 0.698 : -0.371%
bitops-bits-in-byte.js	768 -> 976 : -27.083%	1728 -> 1720 : +0.463%	1.019 -> 1.015 : +0.398%
bitops-bitwise-and.js	544 -> 744 : -36.765%	1480 -> 1472 : +0.541%	1.227 -> 1.214 : +1.041%
bitops-nsieve-bits.js	60952 -> 61176 : -0.368%	1728 -> 1720 : +0.463%	1.475 -> 1.481 : -0.387%
controlflow-recursive.js	1048 -> 1280 : -22.137%	61592 -> 63624 : -3.299%	0.517 -> 0.517 : +0.067%
crypto-aes.js	27904 -> 27888 : +0.057%	2288 -> 2312 : -1.049%	0.880 -> 0.882 : -0.169%
crypto-md5.js	70640 -> 70960 : -0.453%	1796 -> 1788 : +0.445%	0.733 -> 0.735 : -0.335%
crypto-sha1.js	45984 -> 46320 : -0.731%	1856 -> 1848 : +0.431%	0.756 -> 0.754 : +0.241%
crypto.js	50664 -> 51696 : -2.037%	3164 -> 3228 : -2.023%	8.676 -> 8.654 : +0.250%
date-format-tofte.js	8688 -> 9168 : -5.525%	2128 -> 2120 : +0.376%	1.008 -> 1.008 : +0.028%
date-format-xparb.js	14912 -> 15256 : -2.307%	2688 -> 2704 : -0.595%	0.819 -> 0.818 : +0.175%
deltablue.js	453256 -> 456496 : -0.715%	3540 -> 3636 : -2.712%	5.446 -> 5.475 : -0.527%
math-cordic.js	1824 -> 2040 : -11.842%	1728 -> 1720 : +0.463%	1.706 -> 1.698 : +0.442%
math-partial-sums.js	1280 -> 1504 : -17.500%	1704 -> 1696 : +0.469%	1.042 -> 1.045 : -0.294%
math-spectral-norm.js	2992 -> 3256 : -8.824%	1728 -> 1720 : +0.463%	0.744 -> 0.743 : +0.113%
raytrace.js	21840 -> 22472 : -2.894%	4952 -> 4844 : +2.181%	2.775 -> 2.835 : -2.130%
richards.js	8216 -> 8560 : -4.187%	2148 -> 2244 : -4.469%	0.309 -> 0.308 : +0.250%
string-base64.js	89856 -> 90096 : -0.267%	1776 -> 1768 : +0.450%	1.413 -> 1.399 : +0.932%
string-fasta.js	4056 -> 4392 : -8.284%	1712 -> 1704 : +0.467%	3.386 -> 3.377 : +0.267%
Geometric mean:	-8.051%	-0.466%	-0.075%

Binary (bytes)	master(de37e1e)	patch(faa948f)	Diff
size	239156	239156	0 bytes
.rodata	20695	20695	0 bytes
.dynstr	285	285	0 bytes
.rel.plt	240	240	0 bytes
.interp	25	25	0 bytes
.dynsym	576	576	0 bytes
.gnu.hash	252	252	0 bytes
.text	211152	211072	-80 bytes
.comment	85	85	0 bytes
.shstrtab	226	226	0 bytes
.data	8	8	0 bytes
.ARM.exidx	8	8	0 bytes
.rel.dyn	16	16	0 bytes
.init	12	12	0 bytes
.got	136	136	0 bytes
.plt	384	384	0 bytes
.note.ABI-tag	32	32	0 bytes
.gnu.version_r	32	32	0 bytes
.bss	1575248	1575064	-184 bytes
.fini	8	8	0 bytes
.hash	220	220	0 bytes
.gnu.version	72	72	0 bytes
.fini_array	4	4	0 bytes
.init_array	4	4	0 bytes
.dynamic	240	240	0 bytes
.eh_frame	4	4	0 bytes
.ARM.attributes	53	53	0 bytes

[zherczeg]

There is a 184 byte bss decrease and a 200 byte heap memory increase because the global object is stored on the heap now. Furthermore byte codes needs an extra 4 byte for realms.

[zherczeg]

There was an 1.5K increase on access-binary-trees.js, so I run this test with --mem-stress-test option. The change was from 27056 to 27344, so the reason of increase is the delayed gc runs. The usual 200 byte increase is also visible.

[rerobika]

LGTM

[rerobika]

Could you please add $test262.createRealm support after #4329?

[zherczeg]

Of course. Next patch will also do several things.

[dbatyai]

LGTM