[AMDGPU] Fix useDeprecatedPositionallyEncodedOperands errors.

[jyknight]

Summary

This is a follow-on to https://reviews.llvm.org/D134073.

The errors in the R600 half were fixed previously in
https://reviews.llvm.org/D134078. Originally, I thought that the fixes
to the AMDGPU half would be tricky, but upon taking another look,
there were only a couple minor issues that needed fixing:

1. Previously, buffer load instructions (BUFFER_LOAD_*_LDS_*) were

populating the vdata field in the instruction from the swz
operand. This was incorrect, but harmless, as when the LDS option is
set, the instruction does not use the vdata field.

2. The BUFFER_STORE_LDS_DWORD_gfx90a instruction was populating

acc from the swz operand, because acc was set to ?. (I believe
that the intent here was to leave the instruction bit as an "unknown
value", but you can't do that except by setting the bits on Inst
directly). Also harmless, for the same reason.

llvm/lib/Target/AMDGPU/AMDGPU.td

 def FeatureISAVersion11_0_3 : FeatureSet<
   !listconcat(FeatureISAVersion11_Common.Features,
     [])>;
 
 //===----------------------------------------------------------------------===//
 
 def AMDGPUInstrInfo : InstrInfo {
   let guessInstructionProperties = 1;
-  let noNamedPositionallyEncodedOperands = 1;
-  let useDeprecatedPositionallyEncodedOperands = 1;
 }
 
 def AMDGPUAsmParser : AsmParser {
   // Some of the R600 registers have the same name, so this crashes.
   // For example T0_XYZW and T0_XY both have the asm name T0.
   let ShouldEmitMatchRegisterName = 0;
 
   // Call the custom operand parser for all operands.

llvm/lib/Target/AMDGPU/BUFInstructions.td

class MUBUF_Real <MUBUF_Pseudo ps, string real_name = ps.Mnemonic> :
   bits<5>  cpol;
   bits<8>  vaddr;
   bits<10> vdata;
   bits<7>  srsrc;
   bits<8>  soffset;
 
   // GFX90A+ only: instruction uses AccVGPR for data
   // Bit supersedes tfe.
-  bits<1> acc = !if(ps.has_vdata, vdata{9}, !if(ps.lds, ?, 0));
+  bits<1> acc = !if(ps.has_vdata, vdata{9}, 0);
 }
 
 
 // For cache invalidation instructions.
 class MUBUF_Invalidate <string opName, SDPatternOperator node = null_frag> :
   MUBUF_Pseudo<opName, (outs), (ins), "", [(node)]> {
 
   let AsmMatchConverter = "";
: MUBUF_Pseudo<opName,
                  pattern>,
     MUBUF_SetupAddr<addrKindCopy> {
   let PseudoInstr = opName # !if(isLds, "_lds", "") # !if(isTFE, "_tfe", "") #
                     "_" # getAddrName<addrKindCopy>.ret;
   let AsmMatchConverter = "cvtMubuf";
 
   let Constraints = !if(HasTiedDest, "$vdata = $vdata_in", "");
   let LGKM_CNT = isLds;
-  let has_vdata = !not(isLdsOpc);
+  let has_vdata = !not(!or(isLds, isLdsOpc));
   let mayLoad = 1;
   let mayStore = isLds;
   let maybeAtomic = 1;
   let Uses = !if(!or(isLds, isLdsOpc) , [EXEC, M0], [EXEC]);
   let tfe = isTFE;
   let lds = isLds;
   let elements = getMUBUFElements<vdata_vt>.ret;
   let VALU = isLds;