Fix string comparison code generation

[feds01]

Description

This patch fixes a bug with code generation not generating the required code for string comparisons in some cases. This resulted into odd behaviour when writing code like:

foo := () => "hello"

main := () => {
  if "hello" == foo() {
     println("yes!")
  }
}

The existing implementation tried to compare by ptr which inevitably failed due to the strs having different base addresses. Hence, in the above example, `yes! would not be printed.

This now properly invokes str_eq in all string comparison cases, and ensures that string comparisons behave as expected.

Commits

• lower/reporting: fix comment typos
• reporting: convert note_on_span! into function
• repr: fix invalid ReprTy::is_scalar implementation
• lower: correctly handle string comparisons
• lower: re-factor non_scalar_compare to use build_non_scalar_binary_compare
• tests: re-generate strings_in_matches stdout