[RISCV] Update error message to not call 'RV32' and 'RV64' an extension.

[craig.topper]

Summary

I used RV32 so I didn't have to write RV32I and RV32E. Ideally
these builtins will be wrapped in a header someday so long term I don't
expect users to see these errors.

[asb]

LGTM, thanks!

clang/include/clang/Basic/DiagnosticSemaKinds.td

 def err_tcb_conflicting_attributes : Error<
   "attributes '%0(\"%2\")' and '%1(\"%2\")' are mutually exclusive">;
 def warn_tcb_enforcement_violation : Warning<
   "calling %0 is a violation of trusted computing base '%1'">,
   InGroup<DiagGroup<"tcb-enforcement">>;
 
 // RISC-V builtin required extension warning
 def err_riscv_builtin_requires_extension : Error<
-  "builtin requires at least one of the following extensions to be enabled: %0">;
+  "builtin requires%select{| at least one of the following extensions to be enabled}0: %1">;
 def err_riscv_builtin_invalid_lmul : Error<
   "LMUL argument must be in the range [0,3] or [5,7]">;
 
 def err_std_source_location_impl_not_found : Error<
   "'std::source_location::__impl' was not found; it must be defined before '__builtin_source_location' is called">;
 def err_std_source_location_impl_malformed : Error<
   "'std::source_location::__impl' must be standard-layout and have only two 'const char *' fields '_M_file_name' and '_M_function_name', and two integral fields '_M_line' and '_M_column'">;
 

clang/lib/Sema/SemaChecking.cpp

 //===- SemaChecking.cpp - Extra Semantic Checking -------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
bool Sema::CheckRISCVBuiltinFunctionCall(const TargetInfo &TI,
   // Check if each required feature is included
   for (StringRef F : ReqFeatures) {
     SmallVector<StringRef> ReqOpFeatures;
     F.split(ReqOpFeatures, '|');
 
     if (llvm::none_of(ReqOpFeatures,
                       [&TI](StringRef OF) { return TI.hasFeature(OF); })) {
       std::string FeatureStrs;
+      bool IsExtension = true;
       for (StringRef OF : ReqOpFeatures) {
         // If the feature is 64bit, alter the string so it will print better in
         // the diagnostic.
-        if (OF == "64bit")
+        if (OF == "64bit") {
+          assert(ReqOpFeatures.size() == 1 && "Expected '64bit' to be alone");
           OF = "RV64";
-        if (OF == "32bit")
+          IsExtension = false;
+        }
+        if (OF == "32bit") {
+          assert(ReqOpFeatures.size() == 1 && "Expected '32bit' to be alone");
           OF = "RV32";
+          IsExtension = false;
+        }
 
         // Convert features like "zbr" and "experimental-zbr" to "Zbr".
         OF.consume_front("experimental-");
         std::string FeatureStr = OF.str();
         FeatureStr[0] = std::toupper(FeatureStr[0]);
         // Combine strings.
         FeatureStrs += FeatureStrs == "" ? "" : ", ";
         FeatureStrs += "'";
         FeatureStrs += FeatureStr;
         FeatureStrs += "'";
       }
       // Error message
       FeatureMissing = true;
       Diag(TheCall->getBeginLoc(), diag::err_riscv_builtin_requires_extension)
+          << IsExtension
           << TheCall->getSourceRange() << StringRef(FeatureStrs);
     }
   }
 
   if (FeatureMissing)
     return true;
 
   switch (BuiltinID) {

clang/test/CodeGen/RISCV/rvb-intrinsics/riscv32-zbb-error.c

 // NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
 // RUN: %clang_cc1 -triple riscv32 -target-feature +zbb -verify %s -o -
 
 int orc_b_64(int a) {
-  return __builtin_riscv_orc_b_64(a); // expected-error {{builtin requires at least one of the following extensions to be enabled: 'RV64'}}
+  return __builtin_riscv_orc_b_64(a); // expected-error {{builtin requires: 'RV64'}}
 }

clang/test/CodeGen/RISCV/rvb-intrinsics/riscv64-zbkb-error.c

 // NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
 // RUN: %clang_cc1 -triple riscv64 -target-feature +zbkb -verify %s -o -
 
 int zip(int rs1)
 {
-  return __builtin_riscv_zip_32(rs1); // expected-error {{builtin requires at least one of the following extensions to be enabled: 'RV32'}}
+  return __builtin_riscv_zip_32(rs1); // expected-error {{builtin requires: 'RV32'}}
 }
 
 int unzip(int rs1)
 {
-  return __builtin_riscv_unzip_32(rs1); // expected-error {{builtin requires at least one of the following extensions to be enabled: 'RV32'}}
+  return __builtin_riscv_unzip_32(rs1); // expected-error {{builtin requires: 'RV32'}}
 }