Support homogeneous aggregates for hard-float ARM
Support homogeneous aggregates for hard-float ARM

Hard-float ARM targets use the AACPS-VFP ABI, which passes and returns
homogeneous float/vector aggregates in the VFP registers.

Fixes #43329.

graydon/rust,graydon/rust,GBGamer/rust,aidancully/rust,aidancully/rust,GBGamer/rust,graydon/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,GBGamer/rust,graydon/rust,GBGamer/rust,GBGamer/rust,graydon/rust