Fix failing test

Author: Pouya Yarandi

Sources/SwiftProtobuf/PathDecoder.swift

@@ -35,7 +35,9 @@ extension Message {
     guard let type = Self.self as? any _ProtoNameProviding.Type else {
       return nil
     }
-    return type._protobuf_nameMap.number(forJSONName: field)
+    return Array(field.utf8).withUnsafeBytes { bytes in
+      type._protobuf_nameMap.number(forProtoName: bytes)
+    }
   }
 
   static func name(for field: Int) -> String? {

Tests/SwiftProtobufTests/Test_FieldMask.swift

@@ -213,7 +213,7 @@ final class Test_FieldMask: XCTestCase, PBTestHelpers {
         var message = SwiftProtoTesting_Fuzz_Message()
         message.singularInt32 = 1
         message.SwiftProtoTesting_Fuzz_singularInt32Ext = 1
-        let mask = Google_Protobuf_FieldMask(protoPaths: ["singularString"])
+        let mask = Google_Protobuf_FieldMask(protoPaths: ["singular_string"])
 
         // Checks trim should retain extensions while removes other fields.
         let r1 = message.trim(fieldMask: mask)