[ConstraintSystem] Improve initial constraints printing in the type inference algorithm debug output

[amritpan]

These changes reduce and reformat the initial constraints printed by the type inference algorithm's debug output. By reducing repetitive locators and better sorting the constraints, the possible constraints are easier to follow.

For example, the following disjunctions:

Inactive Constraints:
  disjunction [[locator@0x13b1cf000 [OverloadedDeclRef@/Users/amritpankaur/test.swift:53:5]]]:
>  [favored]  $T0 bound to decl Swift.(file).String extension.+ : (String.Type) -> (String, String) -> String [[locator@0x13b1cf000 [OverloadedDeclRef@/Users/amritpankaur/test.swift:53:5]]];
>             $T0 bound to decl Swift.(file).Duration extension.+ : (Duration.Type) -> (Duration, Duration) -> Duration [[locator@0x13b1cf000 [OverloadedDeclRef@/Users/amritpankaur/test.swift:53:5]]];
>             ... // additional constraints
>             $T0 bound to decl Swift.(file).UInt extension.+ : (UInt.Type) -> (UInt, UInt) -> UInt [[locator@0x13b1cf000 [OverloadedDeclRef@/Users/amritpankaur/test.swift:53:5]]];
>  [favored]  $T0 bound to decl Swift.(file).Int extension.+ : (Int.Type) -> (Int, Int) -> Int [[locator@0x13b1cf000 [OverloadedDeclRef@/Users/amritpankaur/test.swift:53:5]]];
>             $T0 bound to decl _Concurrency.(file).Instant extension.+ : (ContinuousClock.Instant.Type) -> (ContinuousClock.Instant, Duration) -> ContinuousClock.Instant [[locator@0x13b1cf000 [OverloadedDeclRef@/Users/amritpankaur/test.swift:53:5]]];
>             ... // additional constraints

will now print as:

Inactive Constraints:
  disjunction [[locator@0x13aaa7800 [OverloadedDeclRef@/Users/amritpankaur/test.swift:53:5]]]:
>  [favored]  $T0 bound to decl Swift.(file).String extension.+ : (String.Type) -> (String, String) -> String
>  [favored]  $T0 bound to decl Swift.(file).Int extension.+ : (Int.Type) -> (Int, Int) -> Int
>             $T0 bound to decl Swift.(file).Duration extension.+ : (Duration.Type) -> (Duration, Duration) -> Duration
>             ... // additional constraints

[xedin]

Looks great! I have left a couple of comments inline for you to address before we merge.

[xedin]

Great, thank you!

[xedin]

@swift-ci please test

[xedin]

@amritpan Looks like you forgot to adjust one of the tests with checks constraint system output.

[xedin]

@swift-ci please test