orm: init or implementation

[LouisSchmieder]

This PR adds or to the orm:

import sqlite

struct Foo {
	id int [primary; sql: serial]
}

fn main() {
	db := sqlite.connect(':memory:') ?

	mut foo := Foo{}

	sql db {
		insert foo into Foo
	} or {
		eprintln(err)
	}

	res := sql db {
		select from Foo
	} or {
		[]Foo{}
	}


	eprintln(res)
}

TODO:

• Add checker tests
• Add general tests for or expr

[medvednikov]

 FAIL  [ 155/1035]   454.691 ms vlib/orm/orm_test.v
================ V panic ================
   module: builtin
 function: slice()
  message: array.slice: invalid slice index (0 > -1)
     file: /home/runner/work/v/v/vlib/builtin/array.v:485
   v hash: f468883

[LouisSchmieder]

I'll convert it do a draft anyways

[LouisSchmieder]

Thanks @spytheman didn't knew exactly the or things

[medvednikov]

FAIL  [ 156/1038]  6280.150 ms vlib/orm/orm_sql_or_blocks_test.v
[/home/runner/work/v/v/vlib/v/gen/c/sql.v:782] g.inside_call: false
[/home/runner/work/v/v/vlib/v/gen/c/sql.v:782] g.inside_call: false
[/home/runner/work/v/v/vlib/v/gen/c/sql.v:782] g.inside_call: false
Uninitialized bytes in __interceptor_strlen at offset 31 inside [0x703000000578, 32)
==17656==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x7f41c9905c3a  (/lib/x86_64-linux-gnu/libsqlite3.so.0+0x44c3a)
    #1 0x7f41c993de4b  (/lib/x86_64-linux-gnu/libsqlite3.so.0+0x7ce4b)
    #2 0x7f41c99aa10b  (/lib/x86_64-linux-gnu/libsqlite3.so.0+0xe910b)
    #3 0x7aaee4 in sqlite__connect (/tmp/v/test_session_124359337987/orm_sql_or_blocks_test+0x7aaee4)
    #4 0x7b0630 in main__test_ensure_db_exists_and_user_table_is_ok (/tmp/v/test_session_124359337987/orm_sql_or_blocks_test+0x7b0630)
    #5 0x7c35ac in main (/tmp/v/test_session_124359337987/orm_sql_or_blocks_test+0x7c35ac)
    #6 0x7f41c9554082 in __libc_start_main /build/glibc-SzIz7B/glibc-2.31/csu/../csu/libc-start.c:[308](https://github.com/vlang/v/runs/7267602782?check_suite_focus=true#step:7:309):16
    #7 0x41d64d in _start (/tmp/v/test_session_124359337987/orm_sql_or_blocks_test+0x41d64d)

[LouisSchmieder]

Will continue this pr after the 1th August probably, bc of holidays

[enghitalo]

Friendly Ping?