[libunwind] [libunwind] Replace process_vm_readv with pipe (PR #74791)

[Jordan R AW via cfe-commits]

================
@@ -2822,13 +2825,18 @@ bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_s390x &) {
   // onto the stack.
   const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
   // The PC might contain an invalid address if the unwind info is bad, so
-  // directly accessing it could cause a segfault. Use process_vm_readv to
+  // directly accessing it could cause a segfault. Use pipe/write/read to
   // read the memory safely instead.
   uint16_t inst;
----------------
ajordanr-google wrote:

Should be removed, since we redefined this lower down on line 2834.

https://github.com/llvm/llvm-project/pull/74791