[clang] [clang] remove lots of "innocuous" addrspacecasts (PR #197745)

[Matt Arsenault via cfe-commits]

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@@ -480,7 +479,6 @@ kernel void test_target_features_kernel(global int *i) {
 // GFX900-NEXT:    [[BLOCK_ASCAST:%.*]] = addrspacecast ptr addrspace(5) [[BLOCK]] to ptr
 // GFX900-NEXT:    [[BLOCK3_ASCAST:%.*]] = addrspacecast ptr addrspace(5) [[BLOCK3]] to ptr
 // GFX900-NEXT:    [[BLOCK12_ASCAST:%.*]] = addrspacecast ptr addrspace(5) [[BLOCK12]] to ptr
-// GFX900-NEXT:    [[BLOCK_SIZES_ASCAST:%.*]] = addrspacecast ptr addrspace(5) [[BLOCK_SIZES]] to ptr
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arsenm wrote:

These cases were just dead instructions? Does that mean there's an unnecessary stripPointerCasts somewhere?

https://github.com/llvm/llvm-project/pull/197745