Revert "Unconditionally increase imemo type size"

We reverted the change in internal/imemo.h, and we should have reverted
yjit and zjit changes, too.

This reverts commit fe9d5c8.

Author: wks

yjit/src/cruby.rs

@@ -742,9 +742,7 @@ mod manual_defs {
     pub const RSTRUCT_EMBED_LEN_MASK: usize = (RUBY_FL_USER7 | RUBY_FL_USER6 | RUBY_FL_USER5 | RUBY_FL_USER4 | RUBY_FL_USER3 |RUBY_FL_USER2 | RUBY_FL_USER1) as usize;
 
     // From iseq.h - via a different constant, which seems to confuse bindgen
-    // MMTk note: After we changed the IMEMO_MASK in imemo.h, we shifted IMEMO_FL_USERx, too.
-    // Now ISEQ_TRANSLATED == IMEMO_FL_USER3 == RUBY_FL_USER8
-    pub const ISEQ_TRANSLATED: usize = RUBY_FL_USER8 as usize;
+    pub const ISEQ_TRANSLATED: usize = RUBY_FL_USER7 as usize;
 
     // We'll need to encode a lot of Ruby struct/field offsets as constants unless we want to
     // redeclare all the Ruby C structs and write our own offsetof macro. For now, we use constants.

zjit/src/cruby.rs

@@ -1026,9 +1026,7 @@ mod manual_defs {
     pub const RSTRUCT_EMBED_LEN_MASK: usize = (RUBY_FL_USER7 | RUBY_FL_USER6 | RUBY_FL_USER5 | RUBY_FL_USER4 | RUBY_FL_USER3 |RUBY_FL_USER2 | RUBY_FL_USER1) as usize;
 
     // From iseq.h - via a different constant, which seems to confuse bindgen
-    // MMTk note: After we changed the IMEMO_MASK in imemo.h, we shifted IMEMO_FL_USERx, too.
-    // Now ISEQ_TRANSLATED == IMEMO_FL_USER3 == RUBY_FL_USER8
-    pub const ISEQ_TRANSLATED: usize = RUBY_FL_USER8 as usize;
+    pub const ISEQ_TRANSLATED: usize = RUBY_FL_USER7 as usize;
 
     // We'll need to encode a lot of Ruby struct/field offsets as constants unless we want to
     // redeclare all the Ruby C structs and write our own offsetof macro. For now, we use constants.