[pseudo] Invert rows/columns of LRTable storage for speedup. NFC

There are more states than symbols.
This means first partioning the action list by state leaves us with a smaller
range to binary search over. This improves find() a lot and glrParse() by 7%.
The tradeoff is storing more smaller ranges increases the size of the offsets
array, overall grammar memory is +1% (337->340KB).

Before:
glrParse    188795975 ns    188778003 ns           77 bytes_per_second=1.98068M/s
After:
glrParse    175936203 ns    175916873 ns           81 bytes_per_second=2.12548M/s

Differential Revision: https://reviews.llvm.org/D127006