LLVM 15 regression: LLVM ERROR: cannot select when lowering "vector @splat" behavior test

[andrewrk]

    LLVM ERROR: Cannot select: 0x7fbada5323a8: v8f16,ch = X86ISD::VBROADCAST_LOAD<(load (s16) from constant-pool)> 0x7fbae24e8678, 0x7fbae36d3cd0, behavior/vector.zig:252:18 @[ behavior/vector.zig:261:25 @[ behavior/vector.zig:283:20 ] ]
      0x7fbae36d3cd0: i64 = X86ISD::WrapperRIP TargetConstantPool:i64<half 0xH4248> 0
        0x7fbae36d36f8: i64 = TargetConstantPool<half 0xH4248> 0
    In function: behavior.vector.test.vector @splat
    error: test...
    error: The following command terminated unexpectedly:
    /Users/runner/work/1/s/build/stage3-release/bin/zig test /Users/runner/work/1/s/test/behavior.zig --test-name-prefix behavior-native-ReleaseSmall--multi-default  -OReleaseSmall --cache-dir /Users/runner/work/1/s/zig-cache --global-cache-dir /Users/runner/.cache/zig --name test -fno-single-threaded -I /Users/runner/work/1/s/test -L /Users/runner/zig+llvm+lld+clang-x86_64-macos-none-0.10.0-dev.60+50aa139d1/lib -isystem /Users/runner/zig+llvm+lld+clang-x86_64-macos-none-0.10.0-dev.60+50aa139d1/include --zig-lib-dir /Users/runner/work/1/s/lib --enable-cache 

Next steps:

• use llvm-reduce to create a test case
• file upstream bug report