Revert r343089 "[AArch64] - Return address signing dwarf support"

This caused the DebugInfo/Sparc/gnu-window-save.ll test to fail.

> Functions that have signed return addresses need additional dwarf support:
> - After signing the LR, and before authenticating it, the LR register is in a
>   state the is unusable by a debugger or unwinder
> - To account for this a new directive, .cfi_negate_ra_state, is added
> - This directive says the signed state of the LR register has now changed,
>   i.e. unsigned -> signed or signed -> unsigned
> - This directive has the same CFA code as the SPARC directive GNU_window_save
>   (0x2d), adding a macro to account for multiply defined codes
> - This patch matches the gcc implementation of this support:
>   https://patchwork.ozlabs.org/patch/800271/
>
> Differential Revision: https://reviews.llvm.org/D50136

llvm-svn: 343103

1 files changed, 0 insertions, 4 deletions

diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index 2899242ee4c..7093446815f 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -1332,10 +1332,6 @@ void FrameEmitterImpl::EmitCFIInstruction(const MCCFIInstruction &Instr) {
     Streamer.EmitIntValue(dwarf::DW_CFA_GNU_window_save, 1);
     return;
 
-  case MCCFIInstruction::OpNegateRAState:
-    Streamer.EmitIntValue(dwarf::DW_CFA_AARCH64_negate_ra_state, 1);
-    return;
-
   case MCCFIInstruction::OpUndefined: {
     unsigned Reg = Instr.getRegister();
     Streamer.EmitIntValue(dwarf::DW_CFA_undefined, 1);