[meta] Use the Rust crate for settings generation;

cranelift/codegen/src/settings.rs

@@ -379,6 +379,8 @@ mod tests {
             f.to_string(),
             "[shared]\n\
              opt_level = \"default\"\n\
+             baldrdash_prologue_words = 0\n\
+             probestack_size_log2 = 12\n\
              enable_verifier = true\n\
              is_pic = false\n\
              colocated_libcalls = false\n\
@@ -387,11 +389,9 @@ mod tests {
              enable_nan_canonicalization = false\n\
              enable_simd = true\n\
              enable_atomics = true\n\
-             baldrdash_prologue_words = 0\n\
              allones_funcaddrs = false\n\
              probestack_enabled = true\n\
              probestack_func_adjusts_sp = false\n\
-             probestack_size_log2 = 12\n\
              jump_tables_enabled = true\n"
         );
         assert_eq!(f.opt_level(), super::OptLevel::Default);