[llvm] [DAG] Add `SDPatternMatch::m_Load` (PR #145481)

[Abhishek Kaushik via llvm-commits]

abhishek-kaushik22 wrote:

The failed test looks unrelated to this `LLVM :: CodeGen/AMDGPU/pal-metadata-3.0-callable-dvgpr.ll`

@RKSimon @mshockwave are there any changes required here?

https://github.com/llvm/llvm-project/pull/145481