implement llvm-cov

[makslevental]

This PR implements a generate-aie-coverage-report build target that generates a test/code coverage report using llvm-cov and llvm-profdata (i.e., you need to compile with clang). This PR also implements an additional CI job that appends the coverage report to every PR (seen below).

[github-actions]

Coverage Report

Created: 2023-11-27 05:39

Click here for information about interpreting this report.

Filename	Function Coverage	Line Coverage	Region Coverage	Branch Coverage
Conversion/AIEVecToLLVM/AIEVecToLLVM.cpp	80.65%	89.84%	77.14%	64.55%
Dialect/AIEVec/TransformOps/DialectExtension.cpp	100.00%	100.00%	100.00%	-
Dialect/AIEVec/Transforms/AIEVecOptimizations.cpp	80.65%	85.13%	83.44%	65.00%
Dialect/AIEVec/Transforms/AIEVectorize.cpp	98.97%	90.62%	87.15%	72.63%
Dialect/AIEVec/Transforms/FoldMulAddChainToConvOp.cpp	92.31%	70.39%	71.32%	51.98%
Dialect/AIEVec/Transforms/VectorToAIEVecConversions.cpp	69.60%	63.04%	48.59%	40.58%
Dialect/AIEVec/Transforms/VectorToVectorConversions.cpp	88.00%	90.34%	88.04%	76.56%
Dialect/AIEX/IR/AIEXDialect.cpp	100.00%	86.27%	88.17%	72.06%
Totals	83.72%	76.59%	68.64%	56.32%

Generated by llvm-cov -- llvm version 14.0.0