[mlir][assemblyFormat] Fix bug when using AttrSizedOperandSegments trait with only non-buildable operand types
When creating an operation with
- AttrSizedOperandSegments trait
- Variadic operands of only non-buildable types
- assemblyFormat to automatically generate the parser
the builder local variable is used, but never declared.
This adds a fix as well as a test for this case as existing ones use buildable types only.
Reviewers: rriddle, Kayjukh, grosser
Reviewed By: Kayjukh
Subscribers: mehdi_amini, jpienaar, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, grosul1, frgossen, llvm-commits
Tags: #mlir, #llvm
Differential Revision: https://reviews.llvm.org/D79004