[AArch64] Add missing "pauth" feature to the .arch_extension directive.

[john.brawn]

LGTM.

[john.brawn]

On second though, looking at D94971, do you want to add a test to llvm/test/MC/AArch64/directive-arch_extension-negative.s?

[MarkMurrayARM]

The negative extension case is funny as the instruction generates hints in a way that the test doesn't like. Its not the same pattern.

[john.brawn]

Fair enough.

llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp

const FeatureBitset Features;
     {"sve", {AArch64::FeatureSVE}},
     {"sve2", {AArch64::FeatureSVE2}},
     {"sve2-aes", {AArch64::FeatureSVE2AES}},
     {"sve2-sm4", {AArch64::FeatureSVE2SM4}},
     {"sve2-sha3", {AArch64::FeatureSVE2SHA3}},
     {"sve2-bitperm", {AArch64::FeatureSVE2BitPerm}},
     {"ls64", {AArch64::FeatureLS64}},
     {"xs", {AArch64::FeatureXS}},
+    {"pauth", {AArch64::FeaturePAuth}},
     // FIXME: Unsupported extensions
     {"pan", {}},
     {"lor", {}},
     {"rdma", {}},
     {"profile", {}},
 };
 
 static void setRequiredFeatureString(FeatureBitset FBS, std::string &Str) {

llvm/test/MC/AArch64/armv8.3a-pauth.s

+// RUN: llvm-mc -triple aarch64-none-linux-gnu -show-encoding -mattr=+pauth   < %s | FileCheck %s
+
+paciasp
+
+// CHECK: .text
+// CHECK: paciasp // encoding: [0x3f,0x23,0x03,0xd5]

llvm/test/MC/AArch64/directive-arch_extension.s

 
 .arch_extension rcpc
 ldapr x0, [x1]
 // CHECK: ldapr x0, [x1]
 
 .arch_extension ls64
 ld64b x0, [x13]
 // CHECK: ld64b x0, [x13]
+
+.arch_extension pauth
+paciasp
+// CHECK: paciasp