runtime: move mincore from stubs.go to os_linux.go

Although mincore is declared in stubs.go, mincore isn't used by any
OSes except linux. Move it to os_linux.go and clean up unused code.

Change-Id: I6cfb0fed85c0317a4d091a2722ac55fa79fc7c9a
Reviewed-on: https://go-review.googlesource.com/54910Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/runtime/os_linux.go

@@ -193,6 +193,8 @@ const (
 
 var procAuxv = []byte("/proc/self/auxv\x00")
 
+func mincore(addr unsafe.Pointer, n uintptr, dst *byte) int32
+
 func sysargs(argc int32, argv **byte) {
 	n := argc + 1
 

src/runtime/stubs.go

@@ -131,7 +131,6 @@ func noescape(p unsafe.Pointer) unsafe.Pointer {
 func cgocallback(fn, frame unsafe.Pointer, framesize, ctxt uintptr)
 func gogo(buf *gobuf)
 func gosave(buf *gobuf)
-func mincore(addr unsafe.Pointer, n uintptr, dst *byte) int32
 
 //go:noescape
 func jmpdefer(fv *funcval, argp uintptr)

src/runtime/sys_darwin_arm.s

@@ -19,7 +19,6 @@
 #define	SYS_mmap           197
 #define	SYS_munmap         73
 #define	SYS_madvise        75
-#define	SYS_mincore        78
 #define	SYS_gettimeofday   116
 #define	SYS_kill           37
 #define	SYS_getpid         20
@@ -150,15 +149,6 @@ TEXT runtime·setitimer(SB),NOSPLIT,$0
 	SWI	$0x80
 	RET
 
-TEXT runtime·mincore(SB),NOSPLIT,$0
-	MOVW	addr+0(FP), R0
-	MOVW	n+4(FP), R1
-	MOVW	dst+8(FP), R2
-	MOVW	$SYS_mincore, R12
-	SWI	$0x80
-	MOVW	R0, ret+12(FP)
-	RET
-
 TEXT runtime·walltime(SB), 7, $32
 	MOVW	$8(R13), R0  // timeval
 	MOVW	$0, R1  // zone

src/runtime/sys_darwin_arm64.s

@@ -19,7 +19,6 @@
 #define	SYS_mmap           197
 #define	SYS_munmap         73
 #define	SYS_madvise        75
-#define	SYS_mincore        78
 #define	SYS_gettimeofday   116
 #define	SYS_kill           37
 #define	SYS_getpid         20