runtime: remove unused runtime·signame and runtime·newError

R=golang-dev
CC=golang-dev
https://golang.org/cl/5756044

src/pkg/runtime/runtime.h

@@ -675,7 +675,6 @@ void	runtime·panicslice(void);
 /*
  * runtime c-called (but written in Go)
  */
-void	runtime·newError(String, Eface*);
 void	runtime·printany(Eface);
 void	runtime·newTypeAssertionError(String*, String*, String*, String*, Eface*);
 void	runtime·newErrorString(String, Eface*);
@@ -706,7 +705,6 @@ float64	runtime·ldexp(float64 d, int32 e);
 float64	runtime·modf(float64 d, float64 *ip);
 void	runtime·semacquire(uint32*);
 void	runtime·semrelease(uint32*);
-String	runtime·signame(int32 sig);
 int32	runtime·gomaxprocsfunc(int32 n);
 void	runtime·procyield(uint32);
 void	runtime·osyield(void);

src/pkg/runtime/signal_plan9_386.c

@@ -4,12 +4,6 @@
 
 #include "runtime.h"
 
-String
-runtime·signame(int32)
-{
-	return runtime·emptystring;
-}
-
 void
 runtime·sigenable(uint32 sig)
 {

src/pkg/runtime/signal_unix.c

@@ -10,14 +10,6 @@
 
 extern SigTab runtime·sigtab[];
 
-String
-runtime·signame(int32 sig)
-{
-	if(sig < 0 || sig >= NSIG)
-		return runtime·emptystring;
-	return runtime·gostringnocopy((byte*)runtime·sigtab[sig].name);
-}
-
 void
 runtime·initsig(void)
 {

src/pkg/runtime/thread_windows.c

@@ -302,21 +302,6 @@ runtime·initsig(void)
 	USED(p);
 }
 
-String
-runtime·signame(int32 sig)
-{
-	int8 *s;
-
-	switch(sig) {
-	case SIGINT:
-		s = "SIGINT: interrupt";
-		break;
-	default:
-		return runtime·emptystring;
-	}
-	return runtime·gostringnocopy((byte*)s);
-}
-
 uint32
 runtime·ctrlhandler1(uint32 type)
 {