Document ld -t behaviour

* NEWS: Mention -t change.
	* ld.texi (--trace/-t): Expand documentation a little.

ld/ChangeLog

@@ -1,3 +1,8 @@
+2019-01-31  Alan Modra  <amodra@gmail.com>
+
+	* NEWS: Mention -t change.
+	* ld.texi (--trace/-t): Expand documentation a little.
+
 2019-01-29  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR ld/24008

ld/NEWS

@@ -6,6 +6,12 @@ Changes in 2.32:
 
 * Add support for the C-SKY processor series.
 
+* -t now doesn't report members within archives, unless -t is given twice.
+  A single -t is now more useful when generating a list of files that should be
+  packaged for a linker bug report.  For example:
+    gcc hello.c -save-temps -Wl,-t | xargs realpath | sort | uniq > files
+    tar cJf test.tar.xz `cat files`
+
 Changes in 2.31:
 
 * Speed up direct linking with DLLs for Cygwin and Mingw targets.

ld/ld.texi

@@ -961,7 +961,11 @@ Enabled by default.
 @cindex input files, displaying
 @item -t
 @itemx --trace
-Print the names of the input files as @command{ld} processes them.
+Print the names of the input files as @command{ld} processes them.  If
+@samp{-t} is given twice then members within archives are also printed.
+@samp{-t} output is useful to generate a list of all the object files
+and scripts involved in linking, for example, when packaging files for
+a linker bug report.
 
 @kindex -T @var{script}
 @kindex --script=@var{script}