[performance] Sharp sed hack to make Token 16 bytes instead of 24.

$ _bin/osh_parse.opt -n benchmarks/testdata/configure-coreutils

BEFORE:

dumb_alloc:
        gNumNew = 3492038
        gNumDelete = 189920
        gMemPos = 77177720

AFTER:

dumb_alloc:
        gNumNew = 3492038
        gNumDelete = 189920
        gMemPos = 74281392

build/dev.sh

@@ -135,8 +135,19 @@ oil-asdl-to-cpp() {
   # Instead of id__Eol_Tok, use Id::Eol_Tok.
   # case lex_mode_e::Expr
 
-  gen-asdl-cpp frontend/syntax.asdl
   gen-asdl-cpp osh/runtime.asdl
+
+  gen-asdl-cpp frontend/syntax.asdl
+
+  # CRAZY SHARP HACK to make Token 16 bytes instead of 24!  (And speck is 8
+  # bytes rather than 12, although we might want to get rid of it.)
+  # Because of C's weak type system (typedef int Id_t), this is better than
+  # changing ASDL.
+  local orig=_build/cpp/syntax_asdl.h 
+  local tmp=_devbuild/tmp/syntax_asdl.h
+  sed 's/Id_t id;/uint16_t id;/g' $orig > $tmp
+  diff -u $orig $tmp || true
+  mv -v $tmp $orig
 }
 
 oil-cpp() {