Add option to objdump/readelf to disable access to debuginfod servers.

* dwarf.c (use_debuginfod): New variable.  Set to 1.
	(load_separate_debug_info): Only call
	debuginfod_fetch_separate_debug_info is use_debuginfod is true.
	(dwarf_select_sections_by_names): Add do-not-use-debuginfod and
	use-debuginfod options.
	(dwarf_select_sections_by_letters): Add D and E options.
	* dwarf.h (use_debuginfod): New extern.
	* objdump.c (usage): Mention the new options.
	* readelf.c (usage): Likewise.
	* doc/binutils.texi: Document the new options.
	* doc/debug-options.texi: Describe the new options.
	* NEWS: Mention the new feature.
	* testsuite/binutils-all/debuginfod.exp: Add tests of the new
	options.

binutils/doc/binutils.texi

@@ -2246,6 +2246,8 @@ objdump [@option{-a}|@option{--archive-headers}]
          @option{--dwarf}[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=str-offsets,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links]]
         [@option{-WK}|@option{--dwarf=follow-links}]
         [@option{-WN}|@option{--dwarf=no-follow-links}]
+        [@option{-wD}|@option{--dwarf=use-debuginfod}]
+        [@option{-wE}|@option{--dwarf=do-not-use-debuginfod}]
         [@option{-L}|@option{--process-links}]
         [@option{--ctf=}@var{section}]
         [@option{-G}|@option{--stabs}]
@@ -4883,6 +4885,8 @@ readelf [@option{-a}|@option{--all}]
          @option{--debug-dump}[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=str-offsets,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links]]
         [@option{-wK}|@option{--debug-dump=follow-links}]
         [@option{-wN}|@option{--debug-dump=no-follow-links}]
+        [@option{-wD}|@option{--debug-dump=use-debuginfod}]
+        [@option{-wE}|@option{--debug-dump=do-not-use-debuginfod}]
         [@option{-P}|@option{--process-links}]
         [@option{--dwarf-depth=@var{n}}]
         [@option{--dwarf-start=@var{n}}]
@@ -5508,7 +5512,8 @@ deduced from the input file
 @cindex separate debug files
 
 debuginfod is a web service that indexes ELF/DWARF debugging resources
-by build-id and serves them over HTTP.
+by build-id and serves them over HTTP.  For more information see:
+@emph{https://sourceware.org/elfutils/Debuginfod.html}
 
 Binutils can be built with the debuginfod client library
 @code{libdebuginfod} using the @option{--with-debuginfod} configure option.
@@ -5520,6 +5525,10 @@ separate debug files when the files are otherwise not found.
 debuginfod is packaged with elfutils, starting with version 0.178.
 You can get the latest version from `https://sourceware.org/elfutils/'.
 
+The DWARF info dumping tools (@command{readelf} and @command{objdump})
+have options to control when they should access the debuginfod
+servers.  By default this access is enabled.
+
 @node Reporting Bugs
 @chapter Reporting Bugs
 @cindex bugs

binutils/doc/debug.options.texi

@@ -68,10 +68,27 @@ chosen when configuring the binutils via the
 @option{--enable-follow-debug-links=no} options.  If these are not
 used then the default is to enable the following of debug links.
 
+Note - if support for the debuginfod protocol was enabled when the
+binutils were built then this option will also include an attempt to
+contact any debuginfod servers mentioned in the @var{DEBUGINFOD_URLS}
+environment variable.  This could take some time to resolve.  This
+behaviour can be disabled via the @option{=do-not-use-debuginfod} debug
+option.
+
 @item N
 @itemx =no-follow-links
 Disables the following of links to separate debug info files.
 
+@item D
+@itemx =use-debuginfod
+Enables contacting debuginfod servers if there is a need to follow
+debug links.  This is the default behaviour.
+
+@item E
+@itemx =do-not-use-debuginfod
+Disables contacting debuginfod servers when there is a need to follow
+debug links.
+
 @item l
 @itemx =rawline
 Displays the contents of the @samp{.debug_line} section in a raw