[temporal] Use callMethod instead of getProperty for from()

Supersedes https://chrome-internal-review.googlesource.com/c/v8/fuzzilli/+/8549326

Bug: 439921647
Change-Id: I6a6a696451e9c6dcc52dca701c390d046d42d30d
Reviewed-on: https://chrome-internal-review.googlesource.com/c/v8/fuzzilli/+/8558119
Commit-Queue: Manish Goregaokar <manishearth@google.com>
Reviewed-by: Matthias Liedtke <mliedtke@google.com>

Author: Manishearth

Sources/Fuzzilli/CodeGen/CodeGenerators.swift

@@ -150,10 +150,9 @@ public let CodeGenerators: [CodeGenerator] = [
                 b.construct(constructor, withArgs: [nanoseconds])
 
             } else {
-                let from = b.getProperty("from", of: constructor)
                 // TODO(manishearth, 439921647) Generate Temporal-like strings
                 let string = b.randomVariable(forUseAs: .string)
-                b.callFunction(from, withArgs: [string])
+                b.callMethod("from", on: constructor, withArgs: [string])
             }
 
         }
@@ -165,7 +164,6 @@ public let CodeGenerators: [CodeGenerator] = [
                 let args = (0...numArgs).map { _ in b.randomVariable(forUseAs: .number) }
                 b.construct(constructor, withArgs: args)
             } else {
-                let from = b.getProperty("from", of: constructor)
                 // Whether to pass a Temporal-like object or a string
                 if Bool.random() {
                     // Durations are simple, they accept an object with optional integer fields for each duration field
@@ -175,11 +173,11 @@ public let CodeGenerators: [CodeGenerator] = [
                             dict[field] = b.randomVariable(forUseAs: .number)
                         }
                     }
-                    b.callFunction(from, withArgs: [ b.createObject(with: dict) ] )
+                    b.callMethod("from", on: constructor, withArgs: [ b.createObject(with: dict) ] )
                 } else {
                     // TODO(manishearth, 439921647) Generate Temporal-like strings
                     let string = b.randomVariable(forUseAs: .string)
-                    b.callFunction(from, withArgs: [string])
+                    b.callMethod("from", on: constructor, withArgs: [string])
 
                 }
             }

Tests/FuzzilliTests/JSTyperTests.swift

@@ -1687,6 +1687,13 @@ class JSTyperTests: XCTestCase {
         XCTAssert(b.type(of: instantBuiltin).Is(.object(ofGroup: "TemporalInstantConstructor")))
         let instantProto = b.getProperty("prototype", of: instantBuiltin)
         XCTAssert(b.type(of: instantProto).Is(.object(ofGroup: "Temporal.Instant.prototype")))
+        let instantFrom = b.getProperty("from", of: instantBuiltin)
+        XCTAssert(b.type(of: instantFrom).Is(.unboundFunction([.plain(.string | .object())] => ILType.jsTemporalInstant, receiver: .jsTemporalInstantConstructor)))
+        let randomString = b.randomVariable(forUseAs: .string)
+        let fromCall = b.callMethod("from", on: instantBuiltin, withArgs: [randomString])
+        XCTAssert(b.type(of: fromCall).Is(.jsTemporalInstant))
+
+
         // We don't test Instant's prototype, since Instant only has nontrivial methods that
         // use options bag types that are still in flux.