message: feat(makefile) Handle the `singlepass-*` pairs in a single place.
diff: @@ -38,7 +38,7 @@ SHELL=/bin/bash
  # | | | | Native | glibc | yes |
  # | | | | | | |
  # | | | Singlepass | JIT | glibc | yes |
  -# | | | | Native | glibc | yes |
  +# | | | | Native | glibc | no |
  # | | | | | | |
  # | | aarch64 | Cranelift | JIT | glibc | yes |
  # | | | | Native | glibc | no |
  @@ -189,14 +189,19 @@ ifneq (, $(findstring llvm,$(compilers)))
  endif
  endif
  +##
  +# The Singlepass case.
  +##
  -
  -ifeq ($(IS_AMD64), 1)
  +# If `compilers` contains `singlepass`.
  +ifneq (, $(findstring singlepass,$(compilers)))
  ifeq ($(IS_WINDOWS), 0)
  - # Singlepass doesn't work with the native engine.
  + if ($(IS_AMD64), 1)
  compilers_engines += singlepass-jit
  endif
  endif
  +endif
  +
  use_system_ffi =
  ifeq ($(IS_AARCH64), 1)
  