This commit adds the initial version of the mlir-query tool, which leverages the pre-existing matchers defined in mlir/include/mlir/IR/Matchers.h
The tool provides the following set of basic queries:
hasOpAttrName(string)
hasOpName(string)
isConstantOp()
isNegInfFloat()
isNegZeroFloat()
isNonZero()
isOne()
isOneFloat()
isPosInfFloat()
isPosZeroFloat()
isZero()
isZeroFloat()
Reviewed By: jpienaar
Differential Revision: https://reviews.llvm.org/D155127
