Checks XS0077 is raised if @name on p:variable is not a proper EQName.
Test ab-variable-043.xml is expected to fail with error code err:XS0077.
<p:declare-step xmlns:err="http://www.w3.org/ns/xproc-error" xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
   <p:output port="result">
   <p:variable name="1var" select="5">
   <p:identity>
      <p:with-input>
         <doc/>
      </p:with-input>
   </p:identity>
</p:declare-step>
New tests for checking EQNames.