patch 8.0.1782: no simple way to label quickfix entries

Problem:    No simple way to label quickfix entries.
Solution:   Add the "module" item, to be used instead of the file name for
            display purposes. (Martin Szamotulski, closes #1757)
diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 0e611f4..050b489 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -4737,6 +4737,7 @@
 		list item is a dictionary with these entries:
 			bufnr	number of buffer that has the file name, use
 				bufname() to get the name
+			module	module name
 			lnum	line number in the buffer (first line is 1)
 			col	column number (first column is 1)
 			vcol	|TRUE|: "col" is visual column
@@ -7221,6 +7222,8 @@
 				buffer
 		    filename	name of a file; only used when "bufnr" is not
 				present or it is invalid.
+		    module	name of a module; if given it will be used in
+				quickfix error window instead of the filename.
 		    lnum	line number in the file
 		    pattern	search pattern used to locate the error
 		    col		column number