source-gen: Don’t add extra line for Editor, NarrowingTransformer

Reverts part of 88f7e0b.
Fix rename of _1138IntegerLiteral (oops)
Finish rename of _1138IntegerLiteral dependants

Seems I missed that one earlier in 076e676.
Add BinaryOperatorExpression to Operation Redhat conversion
Add binaryOperation tests to operation tests
Fix Expression handling in abstract RedHat conversions

Failed for terms wrapped in expressions (without token, therefore not
GroupedExpressions). I used to find that behavior of the RedHat compiler
strange – now I hate it, because I’ll have to do that “is JExpression,
!mainToken exists” check *everywhere*. Gah.

(The test that exposed this bug will be added shortly.)
Add missing abstract backend conversion tests
Add UnaryArithmeticOperation, IdentityOperation, NegationOperation

* IdentityOperation: `+i` (RedHat’s PositiveOp)
* NegationOperation: `-i` (RedHat’s NegativeOp)
* UnaryArithmeticOperation: abstract superclass of both (no RedHat equivalent)