[Bug debug/95695] -gcolumn-info is unstable with LTO and --save-temps

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95695

--- Comment #3 from Martin Liška <marxin at gcc dot gnu.org> ---
And it's not related to LTO, it comes from a pre-processor. So we somehow screw
locations with -E and w/o -E option:

$ g++ -g -O2 demo.C && readelf --wide --debug-dump=info a.out > 1
$ g++ -g -O2 demo.C --save-temps && readelf --wide --debug-dump=info a.out > 2
$ diff -u 1 2 | head
--- 1   2020-06-16 10:59:52.263070583 +0200
+++ 2   2020-06-16 11:00:01.195019658 +0200
@@ -736,7 +736,7 @@
     <541>   DW_AT_name        : (indirect string, offset: 0x8f1): size_t
     <545>   DW_AT_decl_file   : 8
     <546>   DW_AT_decl_line   : 2355
-    <548>   DW_AT_decl_column : 26
+    <548>   DW_AT_decl_column : 29
     <549>   DW_AT_type        : <0xf19>
  <2><54d>: Abbrev Number: 23 (DW_TAG_namespace)