[UpdateTestChecks][NFC] Remove entries with same prefix
[UpdateTestChecks][NFC] Remove entries with same prefix

Matching is 'lossy', triples with same prefix can be dropped.

Differential Revision: https://reviews.llvm.org/D63732

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@364471 91177308-0d34-0410-b5e6-96231b3b80d8

GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm