[AArch64] Add FPAC feature.

Author: ahmedbougacha

llvm/lib/Target/AArch64/AArch64Features.td

@@ -185,6 +185,9 @@ def FeatureJS : ExtensionWithMArch<"jsconv", "JS", "FEAT_JSCVT",
   "Enable Armv8.3-A JavaScript FP conversion instructions",
   [FeatureFPARMv8]>;
 
+def FeatureFPAC : Extension<"fpac", "FPAC", "FEAT_FPAC",
+  "Enable v8.3-A Pointer Authentication Faulting enhancement">;
+
 def FeatureCCIDX : Extension<"ccidx", "CCIDX", "FEAT_CCIDX",
   "Enable Armv8.3-A Extend of the CCSIDR number of sets">;
 

llvm/lib/Target/AArch64/AArch64InstrInfo.td

@@ -276,6 +276,8 @@ def HasMatMulFP32    : Predicate<"Subtarget->hasMatMulFP32()">,
                        AssemblerPredicateWithAll<(all_of FeatureMatMulFP32), "f32mm">;
 def HasMatMulFP64    : Predicate<"Subtarget->hasMatMulFP64()">,
                        AssemblerPredicateWithAll<(all_of FeatureMatMulFP64), "f64mm">;
+def HasFPAC          : Predicate<"Subtarget->hasFPAC())">,
+                       AssemblerPredicateWithAll<(all_of FeatureFPAC), "fpac">;
 def HasXS            : Predicate<"Subtarget->hasXS()">,
                        AssemblerPredicateWithAll<(all_of FeatureXS), "xs">;
 def HasWFxT          : Predicate<"Subtarget->hasWFxT()">,