[Wasm GC] Add Names section support for field names (#3589)

Adds support for GC struct fields in the binary format, implementing
WebAssembly/gc#193

No extra tests needed, see the .fromBinary output which shows this working.

This also has a minor fix in the s-parser, we should not always add a name
to the map of index=>name - only if it exists. Without that fix, the binary
emitter would write out null strings.

1 files changed, 5 insertions, 5 deletions

diff --git a/test/heap-types.wast.fromBinary b/test/heap-types.wast.fromBinary
index 75dcae823..2fe6adbe1 100644
--- a/test/heap-types.wast.fromBinary
+++ b/test/heap-types.wast.fromBinary
@@ -1,11 +1,11 @@
 (module
- (type $struct.A (struct (field i32) (field f32) (field f64)))
+ (type $struct.A (struct (field i32) (field f32) (field $named f64)))
  (type $struct.B (struct (field i8) (field (mut i16)) (field (ref null $struct.A)) (field (mut (ref null $struct.A)))))
  (type $matrix (array (ref null $vector)))
  (type $vector (array (mut f64)))
  (type $anyref_=>_none (func (param anyref)))
  (type $parent (struct ))
- (type $struct.C (struct (field (mut f32))))
+ (type $struct.C (struct (field $named-mut (mut f32))))
  (type $none_=>_none (func))
  (type $rtt_1_$parent_=>_none (func (param (rtt 1 $parent))))
  (type $rtt_$parent_=>_none (func (param (rtt $parent))))
@@ -42,12 +42,12 @@
    )
   )
   (drop
-   (struct.get $struct.A 2
+   (struct.get $struct.A $named
     (local.get $x)
    )
   )
   (drop
-   (struct.get $struct.A 2
+   (struct.get $struct.A $named
     (local.get $x)
    )
   )
@@ -88,7 +88,7 @@
     (i32.const 1)
    )
   )
-  (struct.set $struct.C 0
+  (struct.set $struct.C $named-mut
    (ref.null $struct.C)
    (f32.const 100)
   )