codegen/llvm: add workarounds to loadTruncate() for llvm codegen bugs

for wasm, as a heuritic, only enable truncation for values smaller than 32bits.
 -> the bug is no longer triggered in most use cases (or at least the test suite...)

as for powerpc, adding a redundant `and mask` produces working code.
40528b8a93Xavier Bouchoux committed on 10/8/2023, 9:37:49 AMparent370662c
1 file changedLine totals unavailable