all: replace outdated links

Change-Id: I7156e7858e8f06459818e03729c644d64e04d43c
Reviewed-on: https://go-review.googlesource.com/c/go/+/549356
Reviewed-by: Cherry Mui <[email protected]>
Run-TryBot: shuang cui <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Reviewed-by: Michael Pratt <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: cuishuang

src/debug/elf/elf.go

@@ -13,7 +13,7 @@
  * $FreeBSD: src/sys/sparc64/include/elf.h,v 1.12 2003/09/25 01:10:26 peter Exp $
  * "System V ABI" (http://www.sco.com/developers/gabi/latest/ch4.eheader.html)
  * "ELF for the ARM® 64-bit Architecture (AArch64)" (ARM IHI 0056B)
- * "RISC-V ELF psABI specification" (https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.adoc)
+ * "RISC-V ELF psABI specification" (https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-elf.adoc)
  * llvm/BinaryFormat/ELF.h - ELF constants and structures
  *
  * Copyright (c) 1996-1998 John D. Polstra.  All rights reserved.

src/runtime/pprof/pprof.go

@@ -69,7 +69,7 @@
 // all pprof commands.
 //
 // For more information about pprof, see
-// https://github.com/google/pprof/blob/master/doc/README.md.
+// https://github.com/google/pprof/blob/main/doc/README.md.
 package pprof
 
 import (