[AArch64] NFC: Add RUN lines for streaming-compatible code. (#90617)

The intent is to test lowering of vector operations by scalarization,
for functions that are streaming-compatible (and thus cannot use NEON)
and also don't have the +sve attribute.

The generated code is clearly wrong at the moment, but a series of
patches will follow to fix up all cases to use scalar instructions.

A bit of context:

This work will form the base to decouple SME from SVE later on, as it
will make sure that no NEON instructions are used in
streaming[-compatible] mode. Later this will be followed by a patch that
changes `useSVEForFixedLengthVectors` to only return `true` if SVE is
available for the given runtime mode, at which point I'll change the
`-mattr=+sme -force-streaming-compatible-sve` to `-mattr=+sme
-force-streaming-sve` in the RUN lines, so that the tests are considered
to be executed in Streaming-SVE mode.