(reg_changes_size): Add declaration.

From-SVN: r7863

gcc/regs.h

 /* Define per-register tables for data flow info and register allocation.
-   Copyright (C) 1987, 1993 Free Software Foundation, Inc.
+   Copyright (C) 1987, 1993, 1994 Free Software Foundation, Inc.
 
 This file is part of GNU CC.
 
@@ -53,6 +53,12 @@ extern short *reg_n_sets;
 
 extern short *reg_n_deaths;
 
+/* Indexed by N; says whether a psuedo register N was ever used
+   within a SUBREG that changes the size of the reg.  Some machines prohibit
+   such objects to be in certain (usually floating-point) registers.  */
+
+extern char *reg_changes_size;
+
 /* Get the number of consecutive words required to hold pseudo-reg N.  */
 
 #define PSEUDO_REGNO_SIZE(N) \