[clang] [llvm] [AArch64TargetParser]Fix reconstructFromParsedFeatures ignoring negative features (PR #142236)

[Alexandros Lamprineas via llvm-commits]

================
@@ -60,7 +60,7 @@ uint64_t AArch64::getFMVPriority(ArrayRef<StringRef> Features) {
   ExtensionSet FeatureBits;
   for (const StringRef Feature : Features) {
     std::optional<FMVInfo> FMV = parseFMVExtension(Feature);
-    if (!FMV) {
+    if (!FMV && Feature.starts_with('+')) {
----------------
labrinea wrote:

Is it possible to have empty string? If not then `Feature[0] == '+'` should also work.

https://github.com/llvm/llvm-project/pull/142236