Revert "Reapply D70800: Fix AArch64 AAPCS frame record chain"

This reverts commit 99364552.

That commit caused failed assertions e.g. like this:

$ cat alloca.c
a;
b() {
  float c;
  d();
  a = __builtin_alloca(d);
  c = e();
  f(a);
  return c;
}
$ clang -target aarch64-linux-gnu -c alloca.c -O2
clang: ../lib/Target/AArch64/AArch64InstrInfo.cpp:3446: void
llvm::emitFrameOffset(llvm::MachineBasicBlock&,
llvm::MachineBasicBlock::iterator, const llvm::DebugLoc&, unsigned int,
unsigned int, llvm::StackOffset, const llvm::TargetInstrInfo*,
llvm::MachineInstr::MIFlag, bool, bool, bool*):
Assertion `(DestReg != AArch64::SP || Bytes % 16 == 0) &&
"SP increment/decrement not 16-byte aligned"' failed.