libgo: use SYS_timer_settime32

Musl defines SYS_timer_settime32, not SYS_timer_settime, on 32-bit systems.

Based on patch by Sören Tempel.

Change-Id: I1f3485028d132ceca1aba595325af24b4d72b894
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/420222
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>

libgo/sysinfo.c

diff --git a/libgo/sysinfo.c b/libgo/sysinfo.c
index fc02109..180f5c3 100644
--- a/libgo/sysinfo.c
+++ b/libgo/sysinfo.c
@@ -354,6 +354,11 @@
 };
 #endif
 
+#if !defined(SYS_timer_settime) && defined(SYS_timer_settime32)
+// musl defines SYS_timer_settim32 on 32-bit systems.
+#define SYS_timer_settime SYS_timer_settime32
+#endif
+
 #if defined(HAVE_LOFF_T)
 // loff_t can be defined as a macro; for -fgo-dump-spec make sure we
 // see a typedef.