clif-util: Make the -t flag work with the wasm subcommand (#1105)

* clif-util: Make the `-t` flag work with the `wasm` subcommand

The presence of the flag was checked in the code, so it was essentially already
supported, but it was not properly configured when constructing
the CLI arguments parser.

* clif-util: also enable the `-c` flag for the `wasm` subcommand

Similar to the parent commit, this functionality is already supported, just a
mix up of the CLI parser construction made it not show up.

cranelift/src/clif-util.rs

@@ -119,6 +119,18 @@ fn add_enable_multi_value<'a>() -> clap::Arg<'a, 'a> {
         .help("Enable WASM's multi-value support")
 }
 
+fn add_just_decode_flag<'a>() -> clap::Arg<'a, 'a> {
+    Arg::with_name("just-decode")
+        .short("t")
+        .help("Just decode into Cranelift IR")
+}
+
+fn add_check_translation_flag<'a>() -> clap::Arg<'a, 'a> {
+    Arg::with_name("check-translation")
+        .short("c")
+        .help("Just checks the correctness of Cranelift IR translated from WebAssembly")
+}
+
 /// Returns a vector of clap value options and changes these options into a vector of strings
 fn get_vec(argument_vec: Option<clap::Values>) -> Vec<String> {
     let mut ret_vec: Vec<String> = Vec::new();
@@ -151,6 +163,8 @@ fn add_wasm_or_compile<'a>(cmd: &str) -> clap::App<'a, 'a> {
         .arg(add_debug_flag())
         .arg(add_enable_simd_flag())
         .arg(add_enable_multi_value())
+        .arg(add_just_decode_flag())
+        .arg(add_check_translation_flag())
 }
 
 fn handle_debug_flag(debug: bool) {
@@ -191,17 +205,7 @@ fn main() {
                 .arg(add_input_file_arg())
                 .arg(add_debug_flag()),
         )
-        .subcommand(
+        .subcommand(add_wasm_or_compile("compile"))
-            add_wasm_or_compile("compile")
-                .arg(
-                    Arg::with_name("just-decode")
-                        .short("t")
-                        .help("Just decode WebAssembly to Cranelift IR"),
-                )
-                .arg(Arg::with_name("check-translation").short("c").help(
-                    "Just checks the correctness of Cranelift IR translated from WebAssembly",
-                )),
-        )
         .subcommand(
             add_wasm_or_compile("wasm").arg(
                 Arg::with_name("value-ranges")