Prefer explicit construction to coercion in record initialization

While we support initializing records via coercion from an expression
list, e.g.,

    local x: X = [$x1=1, $x2=2];

this can sometimes obscure the code to readers, e.g., when assigning to
value declared and typed elsewhere. The language runtime has a similar
overhead since instead of just constructing a known type it needs to
check at runtime that the coercion from the expression list is valid;
this can be slower than just writing the readible code in the first
place, see #4559.

With this patch we use explicit construction, e.g.,

    local x = X($x1=1, $x2=2);

scripts/base/protocols/ftp/files.zeek

@@ -43,8 +43,8 @@ function describe_file(f: fa_file): string
 event zeek_init() &priority=5
 	{
 	Files::register_protocol(Analyzer::ANALYZER_FTP_DATA,
-	                         [$get_file_handle = FTP::get_file_handle,
-	                          $describe        = FTP::describe_file]);
+	                         Files::ProtoRegistration($get_file_handle = FTP::get_file_handle,
+	                                                  $describe        = FTP::describe_file));
 	}
 
 event file_over_new_connection(f: fa_file, c: connection, is_orig: bool) &priority=5