Add simple PEFile constructor that can be used to easily load a PE file from disk.

ICSharpCode.Decompiler/Metadata/PEFile.cs

@@ -47,6 +47,12 @@ namespace ICSharpCode.Decompiler.Metadata
 		public PEReader Reader { get; }
 		public MetadataReader Metadata { get; }
 
+		public PEFile(string fileName, bool metadataOnly = false)
+			: this(fileName, new PEReader(new FileStream(fileName, FileMode.Open, FileAccess.Read),
+				metadataOnly ? PEStreamOptions.PrefetchMetadata : PEStreamOptions.PrefetchEntireImage))
+		{
+		}
+
 		public PEFile(string fileName, Stream stream, PEStreamOptions options = PEStreamOptions.Default)
 			: this(fileName, new PEReader(stream, options))
 		{