[mlir][spirv] Fix crash in FuncOpVectorUnroll for dynamic-shaped tensor args (#184626)
FuncOpVectorUnroll::matchAndRewrite iterates over all function arguments
and creates a zero-constant placeholder for any non-vector argument via
rewriter.getZeroAttr(type). For dynamically-shaped tensor types such as
tensor<?x2xi8>, getZeroAttr ultimately calls
DenseIntOrFPElementsAttr::getRaw which asserts that the type has a
static shape.
Add an early pre-check that returns failure() for any non-vector
argument with a dynamically-shaped type. This must be done before any IR
modifications are made, since returning failure() after inlining the
function body would leave the IR in an inconsistent state.
Fixes #148369