--- a/gcc/gimple-low.c	Thu Oct 25 08:08:40 2018 +0900
+++ b/gcc/gimple-low.c	Thu Oct 25 10:21:07 2018 +0900
@@ -1,6 +1,6 @@
 /* GIMPLE lowering pass.  Converts High GIMPLE into Low GIMPLE.
 
-   Copyright (C) 2003-2017 Free Software Foundation, Inc.
+   Copyright (C) 2003-2018 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -110,6 +110,17 @@
 
   i = gsi_last (lowered_body);
 
+  /* If we had begin stmt markers from e.g. PCH, but this compilation
+     doesn't want them, lower_stmt will have cleaned them up; we can
+     now clear the flag that indicates we had them.  */
+  if (!MAY_HAVE_DEBUG_MARKER_STMTS && cfun->debug_nonbind_markers)
+    {
+      /* This counter needs not be exact, but before lowering it will
+	 most certainly be.  */
+      gcc_assert (cfun->debug_marker_count == 0);
+      cfun->debug_nonbind_markers = false;
+    }
+
   /* If the function falls off the end, we need a null return statement.
      If we've already got one in the return_statements vector, we don't
      need to do anything special.  Otherwise build one by hand.  */
@@ -296,6 +307,20 @@
       }
       break;
 
+    case GIMPLE_DEBUG:
+      gcc_checking_assert (cfun->debug_nonbind_markers);
+      /* We can't possibly have debug bind stmts before lowering, we
+	 first emit them when entering SSA.  */
+      gcc_checking_assert (gimple_debug_nonbind_marker_p (stmt));
+      /* Propagate fallthruness.  */
+      /* If the function (e.g. from PCH) had debug stmts, but they're
+	 disabled for this compilation, remove them.  */
+      if (!MAY_HAVE_DEBUG_MARKER_STMTS)
+	gsi_remove (gsi, true);
+      else
+	gsi_next (gsi);
+      return;
+
     case GIMPLE_NOP:
     case GIMPLE_ASM:
     case GIMPLE_ASSIGN:
@@ -330,7 +355,7 @@
 	  }
 
 	if (decl
-	    && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL)
+	    && fndecl_built_in_p (decl, BUILT_IN_NORMAL))
 	  {
 	    if (DECL_FUNCTION_CODE (decl) == BUILT_IN_SETJMP)
 	      {
@@ -503,6 +528,10 @@
 	cannot_fallthru = false;
       break;
 
+    case GIMPLE_DEBUG:
+      gcc_checking_assert (gimple_debug_begin_stmt_p (stmt));
+      break;
+
     default:
       /* This case represents statements to be executed when an
 	 exception occurs.  Those statements are implicitly followed
@@ -645,7 +674,7 @@
 bool
 gimple_seq_may_fallthru (gimple_seq seq)
 {
-  return gimple_stmt_may_fallthru (gimple_seq_last_stmt (seq));
+  return gimple_stmt_may_fallthru (gimple_seq_last_nondebug_stmt (seq));
 }