[RISCV] Merge variable declaration with first assignment. NFC

Author: topperc

llvm/lib/TargetParser/RISCVISAInfo.cpp

@@ -398,11 +398,10 @@ RISCVISAInfo::parseFeatures(unsigned XLen,
 
   for (auto &Feature : Features) {
     StringRef ExtName = Feature;
-    bool Experimental = false;
     assert(ExtName.size() > 1 && (ExtName[0] == '+' || ExtName[0] == '-'));
     bool Add = ExtName[0] == '+';
     ExtName = ExtName.drop_front(1); // Drop '+' or '-'
-    Experimental = stripExperimentalPrefix(ExtName);
+    bool Experimental = stripExperimentalPrefix(ExtName);
     auto ExtensionInfos = Experimental
                               ? ArrayRef(SupportedExperimentalExtensions)
                               : ArrayRef(SupportedExtensions);