[ffi] Construct instance constant directly for entry point pragmas.

When we perform constant evaluation in the CFE, the FFI transform
runs after constant evaluation. Thus, it needs to generate pragmas by
directly producing a constant, rather than calling the pragma
constructor.

Change-Id: I3659fe77fde95e7797550900ff896748996758ea
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/111734
Commit-Queue: Aske Simon Christensen <[email protected]>
Reviewed-by: Daco Harkes <[email protected]>

Author: askeksa

pkg/vm/lib/transformations/ffi.dart

@@ -97,7 +97,9 @@ class FfiTransformer extends Transformer {
 
   final Class intClass;
   final Class doubleClass;
-  final Constructor pragmaConstructor;
+  final Class pragmaClass;
+  final Field pragmaName;
+  final Field pragmaOptions;
 
   final Library ffiLibrary;
   final Class nativeFunctionClass;
@@ -123,7 +125,9 @@ class FfiTransformer extends Transformer {
       : env = new TypeEnvironment(coreTypes, hierarchy),
         intClass = coreTypes.intClass,
         doubleClass = coreTypes.doubleClass,
-        pragmaConstructor = coreTypes.pragmaConstructor,
+        pragmaClass = coreTypes.pragmaClass,
+        pragmaName = coreTypes.pragmaName,
+        pragmaOptions = coreTypes.pragmaOptions,
         ffiLibrary = index.getLibrary('dart:ffi'),
         nativeFunctionClass = index.getClass('dart:ffi', 'NativeFunction'),
         pointerClass = index.getClass('dart:ffi', 'Pointer'),

pkg/vm/lib/transformations/ffi_definitions.dart

@@ -410,8 +410,12 @@ class _FfiDefinitionTransformer extends FfiTransformer {
   }
 
   void _makeEntryPoint(Annotatable node) {
-    node.addAnnotation(ConstructorInvocation(
-        pragmaConstructor, Arguments([StringLiteral("vm:entry-point")])));
+    node.addAnnotation(ConstantExpression(
+        InstanceConstant(pragmaClass.reference, [], {
+          pragmaName.reference: StringConstant("vm:entry-point"),
+          pragmaOptions.reference: NullConstant()
+        }),
+        InterfaceType(pragmaClass, [])));
   }
 
   NativeType _getFieldType(Class c) {