go.sys/all: update #includes to new location
Darwin/amd64 now builds. No others tested yet.
mkall.sh also runs correctly. The updates, which are
substantial, are not yet applied to avoid unnecessary churn.
Restore mkerrors.sh, which is needed in the unix directory.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/122410044
diff --git a/unix/asm_linux_386.s b/unix/asm_linux_386.s
index 30b2207..05cf89a 100644
--- a/unix/asm_linux_386.s
+++ b/unix/asm_linux_386.s
@@ -5,7 +5,7 @@
// TODO(rsc): Rewrite all nn(SP) references into name+(nn-8)(FP)
// so that go vet can check that they are correct.
-#include "../../cmd/ld/textflag.h"
+#include "textflag.h"
//
// System calls for 386, Linux
