[clang] [llvm] [AMDGPU] Extend readlane, writelane and readfirstlane intrinsic lowering for generic types (PR #89217)

[Vikram Hegde via cfe-commits]

================
@@ -0,0 +1,65 @@
+; RUN: llc -stop-after=amdgpu-isel -mtriple=amdgcn-- -mcpu=gfx1100 -verify-machineinstrs -o - %s | FileCheck --check-prefixes=CHECK,ISEL %s
+
+; CHECK-LABEL: name:            basic_readfirstlane_i64
+;       CHECK:    [[TOKEN:%[0-9]+]]{{[^ ]*}} = CONVERGENCECTRL_ANCHOR
----------------
vikramRH wrote:

this is a preexisting error, and the failure is further down the pipeline. (after sreg alloc now i guess), does it make sense to have it as xfail now rather then stopping after isel? 

https://github.com/llvm/llvm-project/pull/89217