doc: update out-of-date comments about runtime/cgo

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5532100

src/cmd/6l/obj.c

@@ -190,7 +190,7 @@ main(int argc, char *argv[])
 	case Hdarwin:	/* apple MACH */
 		/*
 		 * OS X system constant - offset from 0(GS) to our TLS.
-		 * Explained in ../../libcgo/darwin_amd64.c.
+		 * Explained in ../../pkg/runtime/cgo/gcc_darwin_amd64.c.
 		 */
 		tlsoffset = 0x8a0;
 		machoinit();
@@ -209,8 +209,8 @@ main(int argc, char *argv[])
 		/*
 		 * ELF uses TLS offset negative from FS.
 		 * Translate 0(FS) and 8(FS) into -16(FS) and -8(FS).
-		 * Also known to ../../pkg/runtime/linux/amd64/sys.s
-		 * and ../../libcgo/linux_amd64.s.
+		 * Also known to ../../pkg/runtime/sys_linux_amd64.s
+		 * and ../../pkg/runtime/cgo/gcc_linux_amd64.c.
 		 */
 		tlsoffset = -16;
 		elfinit();

src/cmd/8l/obj.c

@@ -218,7 +218,7 @@ main(int argc, char *argv[])
 	case Hdarwin:	/* apple MACH */
 		/*
 		 * OS X system constant - offset from %gs to our TLS.
-		 * Explained in ../../libcgo/darwin_386.c.
+		 * Explained in ../../pkg/runtime/cgo/gcc_darwin_386.c.
 		 */
 		tlsoffset = 0x468;
 		machoinit();
@@ -237,8 +237,8 @@ main(int argc, char *argv[])
 		/*
 		 * ELF uses TLS offsets negative from %gs.
 		 * Translate 0(GS) and 4(GS) into -8(GS) and -4(GS).
-		 * Also known to ../../pkg/runtime/linux/386/sys.s
-		 * and ../../libcgo/linux_386.c.
+		 * Also known to ../../pkg/runtime/sys_linux_386.s
+		 * and ../../pkg/runtime/cgo/gcc_linux_386.c.
 		 */
 		tlsoffset = -8;
 		elfinit();

src/make.bash

@@ -75,7 +75,7 @@ $USE_GO_TOOL ||
 ) || exit 1
 bash "$GOROOT"/src/clean.bash
 
-# pkg builds libcgo and the Go programs in cmd.
+# pkg builds runtime/cgo and the Go programs in cmd.
 for i in lib9 libbio libmach cmd
 do
 	echo; echo; echo %%%% making $i %%%%; echo

src/pkg/runtime/cgo/gcc_darwin_386.c

@@ -39,8 +39,8 @@ inittls(void)
 	 *
 	 * The linker and runtime hard-code these constant offsets
 	 * from %gs where we expect to find m and g.
-	 * Known to ../cmd/8l/obj.c:/468
-	 * and to ../pkg/runtime/darwin/386/sys.s:/468
+	 * Known to ../../../cmd/8l/obj.c:/468
+	 * and to ../sys_darwin_386.s:/468
 	 *
 	 * This is truly disgusting and a bit fragile, but taking care
 	 * of it here protects the rest of the system from damage.

src/pkg/runtime/cgo/gcc_darwin_amd64.c

@@ -27,8 +27,8 @@ inittls(void)
 	 *
 	 * The linker and runtime hard-code these constant offsets
 	 * from %gs where we expect to find m and g.
-	 * Known to ../cmd/6l/obj.c:/8a0
-	 * and to ../pkg/runtime/darwin/amd64/sys.s:/8a0
+	 * Known to ../../../cmd/6l/obj.c:/8a0
+	 * and to ../sys_darwin_amd64.s:/8a0
 	 *
 	 * As disgusting as on the 386; same justification.
 	 */

src/pkg/runtime/mkasmh.sh

@@ -34,8 +34,8 @@ case "$GOARCH" in
 386)
 	# The offsets 0 and 4 are also known to:
 	#	../../cmd/8l/pass.c:/D_GS
-	#	../../libcgo/linux_386.c:/^threadentry
-	#	../../libcgo/darwin_386.c:/^threadentry
+	#	cgo/gcc_linux_386.c:/^threadentry
+	#	cgo/gcc_darwin_386.c:/^threadentry
 	case "$GOOS" in
 	windows)
 		echo '#define	get_tls(r)	MOVL 0x14(FS), r'
@@ -89,8 +89,8 @@ amd64)
 	*)
 		# The offsets 0 and 8 are known to:
 		#	../../cmd/6l/pass.c:/D_GS
-		#	../../libcgo/linux_amd64.c:/^threadentry
-		#	../../libcgo/darwin_amd64.c:/^threadentry
+		#	cgo/gcc_linux_amd64.c:/^threadentry
+		#	cgo/gcc_darwin_amd64.c:/^threadentry
 		#
 		echo '#define	get_tls(r)'
 		echo '#define	g(r) 0(GS)'

src/pkg/runtime/runtime.h

@@ -168,8 +168,8 @@ struct	Gobuf
 };
 struct	G
 {
-	byte*	stackguard;	// cannot move - also known to linker, libmach, libcgo
-	byte*	stackbase;	// cannot move - also known to libmach, libcgo
+	byte*	stackguard;	// cannot move - also known to linker, libmach, runtime/cgo
+	byte*	stackbase;	// cannot move - also known to libmach, runtime/cgo
 	Defer*	defer;
 	Panic*	panic;
 	Gobuf	sched;

src/pkg/runtime/sys_darwin_386.s

@@ -338,7 +338,7 @@ TEXT runtime·setldt(SB),7,$32
 	 * To accommodate that rewrite, we translate the
 	 * address and limit here so that 0x468(GS) maps to 0(address).
 	 *
-	 * See ../../../../libcgo/darwin_386.c for the derivation
+	 * See cgo/gcc_darwin_386.c:/468 for the derivation
 	 * of the constant.
 	 */
 	SUBL	$0x468, BX

src/pkg/runtime/sys_darwin_amd64.s

@@ -327,8 +327,8 @@ TEXT runtime·mach_semaphore_signal_all(SB),7,$0
 // set tls base to DI
 TEXT runtime·settls(SB),7,$32
 	/*
-	* Same as in ../386/sys.s:/ugliness, different constant.
-	* See ../../../../libcgo/darwin_amd64.c for the derivation
+	* Same as in sys_darwin_386.s:/ugliness, different constant.
+	* See cgo/gcc_darwin_amd64.c for the derivation
 	* of the constant.
 	*/
 	SUBQ $0x8a0, DI