Print only literal values when printing literals (#2469)

Current `<<` operator on `Literal` prints `[type].const` with it. But
`[type].const` is rather an instruction than a literal itself, and
printing it with the literals makes less sense when we later have
literals whose type don't have `const` instructions (such as reference
types).

This patch
- Makes `<<` operator on `Literal` print only its value
- Makes wasm-shell's shell interface comply with the spec interpreter's
  printing format (`value : type`).
- Prints wasm-shell's `[trap]` message to stderr

These make all `fix_` routines for spec tests in check.py unnecessary.

1 files changed, 1 insertions, 1 deletions

diff --git a/test/example/c-api-kitchen-sink.txt b/test/example/c-api-kitchen-sink.txt
index 7583a216b..44f40ac4c 100644
--- a/test/example/c-api-kitchen-sink.txt
+++ b/test/example/c-api-kitchen-sink.txt
@@ -2217,7 +2217,7 @@ module s-expr printed (in memory, caller-owned):
   )
  )
 )
-(i32.const 1234)
+1234 : i32
 (module
  (type $v (func))
  (func $func (; 0 ;) (type $v)