[AArch64] Add an SVE target feature to the backend and TargetParser.

The feature will be used properly once assembler/disassembler support
begins to land.

llvm-svn: 307917
diff --git a/llvm/lib/Support/TargetParser.cpp b/llvm/lib/Support/TargetParser.cpp
index 13bb6f2..e8ef1d2 100644
--- a/llvm/lib/Support/TargetParser.cpp
+++ b/llvm/lib/Support/TargetParser.cpp
@@ -452,6 +452,8 @@
     Features.push_back("+ras");
   if (Extensions & AArch64::AEK_LSE)
     Features.push_back("+lse");
+  if (Extensions & AArch64::AEK_SVE)
+    Features.push_back("+sve");
 
   return true;
 }