Fixed Issues / Improvements

• Fix for setting Src1.Length in IGA IR.
• Small refactor to render taget write code generation.
• Avoid splitting RetVal variable into two.
• Not limiting the loop unroll to small loops for high register pressure shaders if constant folding
• Handling the math intrinsics in FindInterestingConstants pass.
• Improve MergeURBWrites to also merge URBWrite instructions with dynamic URB offsets.
• Add support to dump GRF usage chart per instruction. Fix some bugs with variable splitting.
• Add GTPin flags to support L0 driver path
• relax ACC substitution constraints
• Improve ConstantBufferCount estimate
• Merge from IGA; includes new platforms and some IGA IR refactoring.
• Fix to handle a infinite loop stuck issue leading to compilation hang.
• Using attribute SpillMemOffset instead of option -spillMemOffset, so that it is encoded in isa binary.
• Refactor to avoid hard-coded simd size for vertex shader compilation.

Ubuntu 18.04 binary packages for LLVM10/Clang10 are included.