As a follow up to #2825 this pr implements size deduction for nested
arrays.
E.g. `var x: [[i32;];] = ((1,2), (3,4));`.
Also updated the pattern matching logic for arrays, now it also checks
element types of the tuple size being deduced from. As a result code
like `var x: [i32;] = ("foo", "bar");`(note, that it tries to init an
array of i32 with a tuple of strings) fails to compile with a pattern
match error instead of an implicit cast failed error.
Moved some common type-related logic used in type_checker.cpp and
interpreter.cpp to the separate file.
kshokhin
b6d660b4d9