Narrow lvalue checking special case from arrays to array views

[mppf]

Resolves #22330
Resolves #20166

This PR implements Option 2 from #22330 by changing an exception in isLegalLvalueActualArg for arrays into an exception for array views (including slices). That makes arrays more consistent with other types while allowing code assigning to a slice, e.g., A[2..n-1] = 1.0, to continue to work. The rationale for having an exception for array views is 1) they are a pretty special type already and 2) they arguably behave more as a reference than a value (and in the future, might be considered a special kind of reference).

For example, here is a program that previously compiled, but after this PR fails to compile with an lvalue error:

proc processArr(ref X) { }
proc createArr() {
  return [1,2];
}

processArr(createArr()); // error: non-lvalue actual is passed to 'ref' formal 'X' of processArr()

To address this error, a user will need to add a new variable:

var A = createArr();
processArr(A); // OK!

To do so, this PR updates isLegalLvalueActualArg as described above and also updates the code propagating flags to promotion wrapper functions to consider FLAG_REF_TO_CONST_WHEN_CONST_THIS, to address an issue that was revealed in testing. While there, this PR moves the code propagating FLAG_OPERATOR, from initPromotionWrapper to buildEmptyWrapper (where the other flags are handled).

Reviewed by @lydia-duncan - thanks!

• full comm=none testing

[lydia-duncan]

Minor update request to the PR message but otherwise this is great, thanks!