Update LKG WARP version to 1.0.19

[Icohedron]

This PR updates the last-known-good WARP version to 1.0.19 and removes XFAILs from tests that now pass after the update.

[Icohedron]

There is a test failure for WaveOps/WaveActiveAllEqual.fp64.test on amd64 but it passes on ARM64.
https://github.com/llvm/offload-test-suite/actions/runs/24811643905/job/72617582293?pr=1111#step:13:537

The part of the output that is incorrect is the "constant-folding case":

offload-test-suite/test/WaveOps/WaveActiveAllEqual.fp64.test

Lines 42 to 51 in 5744c0e

	// constant folding case
	bool4 ResultCF = WaveActiveAllEqual(double4(1,1,1,1));
	Out[index + TID.x] = ResultCF.x;
	index += 4;
	Out[index + TID.x] = ResultCF.y;
	index += 4;
	Out[index + TID.x] = ResultCF.z;
	index += 4;
	Out[index + TID.x] = ResultCF.w;
	index += 4;

Will merge this PR for now, and triage the issue later.