[intro.object] Remove redundant "non-bit-field"

Author: lprv

source/basic.tex

@@ -3666,7 +3666,7 @@
 const bool b5 = r != &test1;            // always \tcode{true}
 \end{codeblock}
 \end{example}
-The address of a non-bit-field subobject of zero size is
+The address of a subobject of zero size is
 the address of an unspecified byte of storage
 occupied by the complete object of that subobject.