Pass Module directly to do_spirv_val instead of re-parsing binary

Avoids assembling the original module to a binary and then parsing it back.
The validation error context can now use the Module directly for span lookups.

Author: LegNeato

crates/rustc_codegen_spirv/src/link.rs

@@ -273,7 +273,6 @@ fn post_link_single_module(
     // Disassemble the stripped module (unless preserving decorations)
     cg_args.do_disassemble(&module_for_output);
     let spv_binary = module_for_output.assemble();
-    let original_binary_for_spans = original_module_for_spans.assemble();
 
     if let Some(dir) = &cg_args.dump_post_link {
         // FIXME(eddyb) rename `filename` with `file_path` to make this less confusing.
@@ -324,7 +323,7 @@ fn post_link_single_module(
     };
 
     if cg_args.run_spirv_val {
-        do_spirv_val(sess, &spv_binary, &original_binary_for_spans, out_filename, val_options);
+        do_spirv_val(sess, &spv_binary, &original_module_for_spans, out_filename, val_options);
     }
 
     {
@@ -412,7 +411,7 @@ fn do_spirv_opt(
 fn do_spirv_val(
     sess: &Session,
     spv_binary: &[u32],
-    original_binary_for_spans: &[u32],
+    original_module_for_spans: &Module,
     filename: &Path,
     options: spirv_tools::val::ValidatorOptions,
 ) {
@@ -422,14 +421,9 @@ fn do_spirv_val(
     let validator = val::create(sess.target.options.env.parse().ok());
 
     if let Err(e) = validator.validate(spv_binary, Some(options)) {
-        // Parse the ORIGINAL binary (with SrcLocDecoration) to look up source spans
+        // Use the ORIGINAL module (with SrcLocDecoration) to look up source spans
         // Note: We validate the stripped binary, but look up spans in the original
-        let module = with_rspirv_loader(|loader| {
-            rspirv::binary::parse_words(original_binary_for_spans, loader)
-        })
-        .ok();
-
-        let mut ctx = ValidationErrorContext::new(sess, module.as_ref(), filename);
+        let mut ctx = ValidationErrorContext::new(sess, Some(original_module_for_spans), filename);
         ctx.emit_error(&e);
     }
 }