Add support for a ".file 0" directive if supporting DWARF 5 or higher.

[Alan Modra]

Fixes a fail on hppa64-hp-hpux, where anything in the first column is
a label.

	* testsuite/gas/elf/dwarf-5-file0.s: Don't start directives in
	first column.

diff --git a/gas/testsuite/gas/elf/dwarf-5-file0.s b/gas/testsuite/gas/elf/dwarf-5-file0.s
index c00ec5e8bc..1f99c58923 100644
--- a/gas/testsuite/gas/elf/dwarf-5-file0.s
+++ b/gas/testsuite/gas/elf/dwarf-5-file0.s
@@ -1,18 +1,17 @@
 	.text
 
-.file 0
-.line 1
+ .file 0
+ .line 1
 	.long 3
 
-.file 1 "asdf"
-.line 2
+ .file 1 "asdf"
+ .line 2
 	.long 5
 
-.file 0
-.line 4
+ .file 0
+ .line 4
 	.long 3
 
-.file 2 "def"
-.line 5
+ .file 2 "def"
+ .line 5
 	.long 3
-

-- 
Alan Modra
Australia Development Lab, IBM