[AArch64][Build Attributes] Remove assertion

When adding build attributes from assembly, an existing value should not
trigger an assertion. This case is valid, and behavior should remain
consistent between builds with and without assertions.

Author: sivan-shani

llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp

@@ -222,13 +222,9 @@ void AArch64TargetStreamer::emitAttribute(StringRef VendorName, unsigned Tag,
                      "Can not add AArch64 build attribute: An attribute with "
                      "the same tag and a different value already exists");
               return;
-            } else {
-              // Case Item.IntValue == Value, no need to emit twice
-              assert(0 &&
-                     "AArch64 build attribute: An attribute with the same tag "
-                     "and a same value already exists");
-              return;
             }
+            // Case Item.IntValue == Value, no need to emit twice
+            return;
           }
         }
       }