As discussed in #25762, and seen in !13970, there are many tests currently failing in the LLVM way. Both `llvm` and `optllvm` ways: `"AtomicFetch CgStaticPointers CgStaticPointersNoFullLazyness GcStaticPointers ListStaticPointers T12622 decodeMyStack decodeMyStack_underflowFrames t24005 tough tough2 staticcallstack001 staticcallstack002 hpc001 hpc_fork"` I analyse these failures in [this comment](https://gitlab.haskell.org/ghc/ghc/-/issues/25769#note_610795). They reveal that static pointers, IPE information and HPC are not working properly with the LLVM backend. Linux only: `"UnboxedTuples"`, a serious run-time crash tracked in #25770. Darwin only: `"jspace"` (this is #25401). `llvm` way only: `"T22187_run"` (this is fixed by !13936). `optllvm` way only: `"GenDerivOutput GenDerivOutput1_0 GenDerivOutput1_1 LinearListComprehension T10604_deriving T17574 T18052a T18118 T19381 T20275 T21755 T22744 T24224 T24726 drv-empty-data dsrun014 stack_big_ret"` These failures are unrelated to the LLVM backend, and due to the fact that we run the tests with optimisations. They do reveal genuine bugs, some quite serious: - `T20275` is tracked in #25771 (GHC crash in constant folding code) - `LinearListComprehension` is tracked in #25772 (Core Lint linearity failure). Linux only: `"T14251"`. Incorrect runtime result with the LLVM backend and optimisation (tracked in #25773).