[clang] [Clang] Add float type support to __builtin_reduce_add and __builtin_reduce_multipy (PR #120367)

[Simon Pilgrim via cfe-commits]

RKSimon wrote:

> @RKSimon It looks like you started this work with:
> 
>     1. [a23291b](https://github.com/llvm/llvm-project/commit/a23291b7db48670f7c57adcfb45877c826a97f22)
> 
>     2. [8a92c45](https://github.com/llvm/llvm-project/commit/8a92c45e07dc81c83ca3afda3971d98c512429d4)
> 
> If you have time could you take a look and let me know what you think?

fp reductions are a nightmare - every time I thought we were getting somewhere, something else fastmath related causes more headaches.

https://github.com/llvm/llvm-project/pull/120367