Add type validations for function imports (#8478)

Validates that the exported function is a subtype of the import
declaration. Part of #8261.

Example error:

```wast
(module $A
  (func $f (export "f") (param i32) (result i32)
    (local.get 0)
  )
)

(register "A" $A)

(module $B
  (func (import "A" "f") (result i32))
)

;; [trap Imported function A.f with type (func (param i32) (result i32)) isn't compatible with import declaration with type (modulo rec groups): (func (result i32))]
```

Author: stevenfontanella

scripts/test/shared.py

@@ -423,7 +423,7 @@ def get_tests(test_dir, extensions=[], recursive=False):
     'if.wast',      # Requires more precise unreachable validation
     'imports.wast',  # Requires fixing handling of mutation to imported globals
     'proposals/threads/imports.wast',  # Missing memory type validation on instantiation
-    'linking.wast',  # Missing function type validation on instantiation
+    'linking.wast',  # Missing global type validation on instantiation
     'proposals/threads/memory.wast',  # Missing memory type validation on instantiation
     'annotations.wast',  # String annotations IDs should be allowed
     'instance.wast',  # Requires support for table default elements
@@ -445,8 +445,6 @@ def get_tests(test_dir, extensions=[], recursive=False):
     'ref_cast.wast',  # Requires host references to not be externalized i31refs
     'ref_test.wast',  # Requires host references to not be externalized i31refs
     'struct.wast',    # Fails to roundtrip unnamed types e.g. `(ref 0)`
-    'type-rec.wast',  # Missing function type validation on instantiation
-    'type-subtyping.wast',  # ShellExternalInterface::callTable does not handle subtyping
     'memory64.wast',        # Requires validations on the max memory size
     'imports3.wast',  # Requires better checking of exports from the special "spectest" module
     'relaxed_dot_product.wast',   # i16x8.relaxed_dot_i8x16_i7x16_s instruction not supported

src/wasm-interpreter.h

@@ -3510,9 +3510,7 @@ class ModuleRunnerBase : public ExpressionRunner<SubType> {
           if (!MemoryUtils::isSubType(exportedMemory, **memory)) {
             trap("Imported memory isn't compatible.");
           }
-        }
-
-        if (auto** tableDecl = std::get_if<Table*>(&import)) {
+        } else if (auto** tableDecl = std::get_if<Table*>(&import)) {
           auto* importedTable = importResolver->getTableOrNull(
             importable->importNames(), **tableDecl);
           if (!importedTable) {
@@ -3528,7 +3526,21 @@ class ModuleRunnerBase : public ExpressionRunner<SubType> {
                << " isn't compatible with import declaration: " << **tableDecl)
                 .str());
           }
+        } else if (auto** function = std::get_if<Function*>(&import)) {
+          auto exportedFunc = getFunction((*function)->name);
+          if (!Type::isSubType(exportedFunc.type, (*function)->type)) {
+            trap((std::stringstream()
+                  << "Imported function " << importable->importNames()
+                  << " with type "
+                  << exportedFunc.type.getHeapType().getSignature().toString()
+                  << " isn't compatible with import declaration with type "
+                     "(modulo rec groups): "
+                  << (*function)->type.getHeapType().getSignature().toString())
+                   .str());
+          }
         }
+
+        // TODO: remaining cases e.g. globals and tags.
       });
   }