[AArch64][SVE] Fix dup/dupq intrinsics for C++.

[sdesmalen]

Summary

This patch changes the builtin prototype to use 'b' (boolean) instead
of the default integer element type. That fixes the dup/dupq intrinsics
when compiling with C++.

This patch also fixes one of the defines for __ARM_FEATURE_SVE2_BITPERM.

[kmclaughlin]

LGTM!

clang/include/clang/Basic/arm_sve.td

 def SVRAX1   : SInst<"svrax1[_{d}]",   "ddd", "lUl", MergeNone, "aarch64_sve_rax1", [IsOverloadNone]>;
 }
 
 let ArchGuard = "defined(__ARM_FEATURE_SVE2_SM4)" in {
 def SVSM4E    : SInst<"svsm4e[_{d}]",    "ddd", "Ui", MergeNone, "aarch64_sve_sm4e", [IsOverloadNone]>;
 def SVSM4EKEY : SInst<"svsm4ekey[_{d}]", "ddd", "Ui", MergeNone, "aarch64_sve_sm4ekey", [IsOverloadNone]>;
 }
 
-let ArchGuard = "__ARM_FEATURE_SVE2_BITPERM" in {
+let ArchGuard = "defined (__ARM_FEATURE_SVE2_BITPERM)" in {
 def SVBDEP   : SInst<"svbdep[_{d}]",   "ddd", "UcUsUiUl", MergeNone, "aarch64_sve_bdep_x">;
 def SVBDEP_N : SInst<"svbdep[_n_{d}]", "dda", "UcUsUiUl", MergeNone, "aarch64_sve_bdep_x">;
 def SVBEXT   : SInst<"svbext[_{d}]",   "ddd", "UcUsUiUl", MergeNone, "aarch64_sve_bext_x">;
 def SVBEXT_N : SInst<"svbext[_n_{d}]", "dda", "UcUsUiUl", MergeNone, "aarch64_sve_bext_x">;
 def SVBGRP   : SInst<"svbgrp[_{d}]",   "ddd", "UcUsUiUl", MergeNone, "aarch64_sve_bgrp_x">;
 def SVBGRP_N : SInst<"svbgrp[_n_{d}]", "dda", "UcUsUiUl", MergeNone, "aarch64_sve_bgrp_x">;
 }

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_dup.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_dupq.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4

clang/utils/TableGen/SveEmitter.cpp

 // Type implementation
 //===----------------------------------------------------------------------===//
 
 std::string SVEType::builtin_str() const {
   std::string S;
   if (isVoid())
     return "v";
 
+  if (isScalarPredicate())
+    return "b";
+
   if (isVoidPointer())
     S += "v";
   else if (!isFloatingPoint())
     switch (ElementBitwidth) {
     case 1: S += "b"; break;
     case 8: S += "c"; break;
     case 16: S += "s"; break;
     case 32: S += "i"; break;