[pph] Force token location for replayed macro definitions (issue4905050)

diff --git a/gcc/cp/pph-streamer-in.c b/gcc/cp/pph-streamer-in.c
index f87e6a5..8d25de8 100644
--- a/gcc/cp/pph-streamer-in.c
+++ b/gcc/cp/pph-streamer-in.c
@@ -1485,6 +1485,7 @@  pph_read_file_1 (pph_stream *stream)
   tree t, file_keyed_classes, file_static_aggregates;
   unsigned i;
   VEC(tree,gc) *file_unemitted_tinfo_decls;
+  source_location cpp_token_replay_loc;
 
   if (flag_pph_debug >= 1)
     fprintf (pph_logfile, "PPH: Reading %s\n", stream->name);
@@ -1502,8 +1503,13 @@  pph_read_file_1 (pph_stream *stream)
     report_validation_error (stream->name, bad_use->ident_str, cur_def,
                              bad_use->before_str, bad_use->after_str);
 
-  /* Re-instantiate all the pre-processor symbols defined by STREAM.  */
-  cpp_lt_replay (parse_in, &idents_used);
+  /* Re-instantiate all the pre-processor symbols defined by STREAM.  Force
+     their source_location to column 0 of the line the include occured on,
+     this avoids shifting all of the line_table's location as we would by adding
+     locations which wouldn't be there in the non-pph compile; thus working
+     towards an identical line_table in pph and non-pph.  */
+  cpp_token_replay_loc = linemap_position_for_column (line_table, 0);
+  cpp_lt_replay (parse_in, &idents_used, &cpp_token_replay_loc);
 
   /* Read in STREAM's line table and merge it in the current line table.  */
   pph_in_and_merge_line_table (stream, line_table);
diff --git a/libcpp/include/symtab.h b/libcpp/include/symtab.h
index b5d6492..c39fa26 100644
--- a/libcpp/include/symtab.h
+++ b/libcpp/include/symtab.h
@@ -20,6 +20,7 @@  along with this program; see the file COPYING3.  If not see
 #define LIBCPP_SYMTAB_H
 
 #include "obstack.h"
+#include "line-map.h"
 
 #ifndef GTY
 #define GTY(x) /* nothing */
@@ -167,7 +168,8 @@  cpp_lt_verify (struct cpp_reader *reader, cpp_idents_used* identifiers,
 /* Replay the macro definitions captured by the table of IDENTIFIERS
    into the READER state.  */
 void
-cpp_lt_replay (struct cpp_reader *reader, cpp_idents_used* identifiers);
+cpp_lt_replay (struct cpp_reader *reader, cpp_idents_used* identifiers,
+               source_location *loc);
 
 /* Destroy IDENTIFIERS captured.  */
 void
diff --git a/libcpp/symtab.c b/libcpp/symtab.c
index aad7277..b2e72f1 100644
--- a/libcpp/symtab.c
+++ b/libcpp/symtab.c
@@ -818,10 +818,12 @@  cpp_lt_define_syntax (char *needed, const char *ident, const char *given)
 }
 
 /* Replay the macro definitions captured by the table of IDENTIFIERS
-   into the READER state.  */
+   into the READER state.  If LOC is non-null, assign *LOC as the
+   source_location to all macro definitions replayed.  */
 
 void
-cpp_lt_replay (cpp_reader *reader, cpp_idents_used* identifiers)
+cpp_lt_replay (cpp_reader *reader, cpp_idents_used* identifiers,
+               source_location *loc)
 {
   unsigned int i;
   unsigned int num_entries = identifiers->num_entries;
@@ -832,6 +834,9 @@  cpp_lt_replay (cpp_reader *reader, cpp_idents_used* identifiers)
   /* Prevent the lexer from invalidating the tokens we've read so far.  */
   reader->keep_tokens++;
 
+  if (loc)
+    cpp_force_token_locations (reader, loc);
+
   for (i = 0; i < num_entries; ++i)
     {
       cpp_ident_use *entry = entries + i;
@@ -865,6 +870,9 @@  cpp_lt_replay (cpp_reader *reader, cpp_idents_used* identifiers)
 
   reader->keep_tokens--;
 
+  if (loc)
+    cpp_stop_forcing_token_locations (reader);
+
   free (buffer);
 }