enable wasm multivalue in zig 0.12+

also fix wasm exportable check

build.zig

@@ -318,7 +318,7 @@ fn buildWasm(
         else => optimize,
     };
     // https://webassembly.org/features/
-    const features = std.Target.wasm.featureSet(&.{
+    var features = std.Target.wasm.featureSet(&.{
         .atomics,
         .bulk_memory,
         // .exception_handling,
@@ -333,7 +333,9 @@ fn buildWasm(
         .simd128,
         // .tail_call,
     });
-    // TODO features.addFeature(@intFromEnum(std.Target.wasm.Feature.multivalue));
+    if (builtin.zig_version.order(try std.SemanticVersion.parse("0.12.0")) != .lt) {
+        features.addFeature(@intFromEnum(std.Target.wasm.Feature.multivalue));
+    }
     const freestanding = if (@hasDecl(std.Build, "resolveTargetQuery"))
         b.resolveTargetQuery(.{
             .cpu_arch = .wasm32,

src/lib/bindings/wasm.zig

@@ -4,6 +4,7 @@ const std = @import("std");
 const assert = std.debug.assert;
 
 const Enum = if (@hasField(std.builtin.Type, "enum")) .@"enum" else .Enum;
+const Strong = if (@hasField(std.builtin.GlobalLinkage, "strong")) .strong else .Strong;
 
 pub const options = pkmn.options;
 
@@ -48,8 +49,8 @@ pub fn gen(comptime num: comptime_int) type {
 }
 
 pub fn exports() type {
-    @export(gen(1).update, .{ .name = "GEN1_update", .linkage = .Strong });
-    @export(gen(1).choices, .{ .name = "GEN1_choices", .linkage = .Strong });
+    @export(gen(1).update, .{ .name = "GEN1_update", .linkage = Strong });
+    @export(gen(1).choices, .{ .name = "GEN1_choices", .linkage = Strong });
     return struct {};
 }
 

src/lib/wasm.zig

@@ -9,7 +9,7 @@ export const CALC = wasm.options.calc;
 export const GEN1_CHOICES_SIZE = wasm.gen(1).CHOICES_SIZE;
 export const GEN1_LOGS_SIZE = wasm.gen(1).LOGS_SIZE;
 
-const exportable = @hasDecl(std.zig, "Zir") and !@hasDecl(std.zig.Zir.Inst, "export_value");
+const exportable = @hasDecl(std.zig, "Zir") and !@hasField(std.zig.Zir.Inst.Tag, "export_value");
 
 usingnamespace if (exportable) struct {
     export const GEN1_update = wasm.gen(1).update;