e276dcec17
Disallows initialization of scalable vectors with an attribute of arbitrary values, e.g.: ```mlir %c = arith.constant dense<[0, 1]> : vector<[2] x i32> ``` Initialization using vector splats remains allowed (i.e. when all the init values are identical): ```mlir %c = arith.constant dense<[1, 1]> : vector<[2] x i32> ``` Note: This is a re-upload of #86178