Add initial support for the convergent attribute.

llvm-svn: 238264

llvm/lib/Bitcode/Writer/BitcodeWriter.cpp

@@ -166,6 +166,8 @@ static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
     return bitc::ATTR_KIND_BUILTIN;
   case Attribute::ByVal:
     return bitc::ATTR_KIND_BY_VAL;
+  case Attribute::Convergent:
+    return bitc::ATTR_KIND_CONVERGENT;
   case Attribute::InAlloca:
     return bitc::ATTR_KIND_IN_ALLOCA;
   case Attribute::Cold: