[committed] Fix rx build failure in libgcc

[Jeff Law]

The rx port has a bunch of what I presume are ABI compatibility 
functions in libgcc.  Those compatibility functions routines such as 
__eqdf2 from libgcc, but without a prototype.  This patch adds the 
missing prototypes.

Pushed to the trunk,
Jeff
commit f1fdd2839ccbc1028b59fbaa7f342e41e3bef848
Author: Jeff Law <j...@ventanamicro.com>
Date:   Sat Dec 2 22:07:59 2023 -0700

    [committed] Fix rx build failure in libgcc
    
    The rx port has a bunch of what I presume are ABI compatibility functions in
    libgcc.  Those compatibility functions routines such as __eqdf2 from libgcc,
    but without a prototype.  This patch adds the missing prototypes.
    
    libgcc/
            * config/rx/rx-abi-functions.c (__ltdf2, __gtdf2): Add prototype.
            (__ledf2, __gedf2, __eqdf2, __nedf2): Likewise.
            (__ltsf2, __gtsf2, __lesf2, __gesf2, __eqsf2, __nesf2): Likewise.

diff --git a/libgcc/config/rx/rx-abi-functions.c 
b/libgcc/config/rx/rx-abi-functions.c
index f505d7d24c3..fc96e4ff171 100644
--- a/libgcc/config/rx/rx-abi-functions.c
+++ b/libgcc/config/rx/rx-abi-functions.c
@@ -33,6 +33,13 @@
 
 #ifdef __RX_64BIT_DOUBLES__
 
+extern int __ltdf2 (double, double);
+extern int __gtdf2 (double, double);
+extern int __ledf2 (double, double);
+extern int __gedf2 (double, double);
+extern int __eqdf2 (double, double);
+extern int __nedf2 (double, double);
+
 int _COM_CMPLTd (double a, double b) { return __ltdf2 (a, b) == -1; }
 int _COM_CMPGTd (double a, double b) { return __gtdf2 (a, b) == 1; }
 int _COM_CMPLEd (double a, double b) { return __ledf2 (a, b) != 1; }
@@ -49,6 +56,13 @@ int _COM_CMPNEf (double, double) __attribute__ ((weak, alias 
("_COM_CMPNEd")));
 
 #else /* 32-bit doubles.  */
 
+extern int __ltsf2 (float, float);
+extern int __gtsf2 (float, float);
+extern int __lesf2 (float, float);
+extern int __gesf2 (float, float);
+extern int __eqsf2 (float, float);
+extern int __nesf2 (float, float);
+
 double _COM_CONVfd (float a) { return a; }
 float  _COM_CONVdf (double a) { return a; }