On #1471, @gasche wrote:

[T]he test file testsuite/tests/typing-misc/pr6939.ml-noflat is broken. When -no-flat-float-array is set, the following definitions should be accepted as valid recursive definitions:

let rec x = [| x |]; 1.;;
let rec x = let u = [|y|] in 10. and y = 1.;;

and currently they are rejected.

This PR adds a check for -no-flat-float-array in the let-rec checking code so that the definitions are accepted and the failing pr6939.ml-noflat passes.