feat: add assignment, bit, and boolean operators

[Wodann]

This PR adds:

• bool assignment operator
• struct assignment operator (both for struct(value) and struct(gc))
• bool and/or (a && b || c)
• bitwise and/or/xor operations for all integer types and bool (a | b & c, a |= b, a &= b)
• left-shift and right-shift (-assignment) operations for all integer types ( a >> b, a << b, a >>= b, a <<= b)

Tasks that were not done yet, but should be in a future PR:

• Add tests for operator errors
• left-shift and right-shift operations should work for all combinations of integer types. Currently it only works when the same integer type is used on the lhs and rhs of the expression. This is currently impossible as a result of this Diagnostic

[discussion] Do we want to use the ^ sign for bitwise xor or the power operator? We've decided to use the ^ sign for bitwise xor

[codecov]

Codecov Report

Merging #144 into master will increase coverage by 0.21%.
The diff coverage is 84.16%.

@@            Coverage Diff             @@
##           master     #144      +/-   ##
==========================================
+ Coverage   82.04%   82.26%   +0.21%     
==========================================
  Files         160      160              
  Lines       10826    11022     +196     
==========================================
+ Hits         8882     9067     +185     
- Misses       1944     1955      +11     

Impacted Files	Coverage Δ
crates/mun_syntax/src/tests/lexer.rs	100.00% <ø> (ø)
crates/mun_syntax/src/parsing/parser.rs	82.35% <50.00%> (+1.43%)	⬆️
crates/mun_syntax/src/syntax_kind/generated.rs	65.31% <54.16%> (+1.42%)	⬆️
crates/mun_codegen/src/ir/body.rs	84.80% <79.68%> (+2.23%)	⬆️
crates/mun_hir/src/ty/op.rs	83.33% <88.88%> (+6.06%)	⬆️
crates/mun_hir/src/expr.rs	88.70% <90.90%> (+0.08%)	⬆️
crates/mun_codegen/src/test.rs	98.11% <100.00%> (+0.52%)	⬆️
crates/mun_hir/src/builtin_type.rs	50.94% <100.00%> (+1.92%)	⬆️
crates/mun_hir/src/ty/infer.rs	73.67% <100.00%> (+0.12%)	⬆️
crates/mun_syntax/src/ast/expr_extensions.rs	92.13% <100.00%> (+0.67%)	⬆️
... and 8 more

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[baszalmstra]

Personally I think we should use ^ for xor.

This PR looks great! Very well done!! 👍

[Wodann]

I agree. In that case I will add ^ and ^= for xor.

[Wodann]

I've added the bitwise xor operator as well as the left-shift and right-shift operators. For scrutiny, could you please check the changed files @baszalmstra ?

[baszalmstra]

Still looks good to me!