Merge pull request dotnet/coreclr#6094 from mikedn/x86-uncontained-long

Allow uncontained GT_LONG nodes

Commit migrated from https://github.com/dotnet/coreclr/commit/ec8157edd52146b108b02d821d88d295048d5212

diff --cc src/coreclr/src/jit/codegenxarch.cpp
Simple merge

diff --cc src/coreclr/src/jit/gentree.cpp
Simple merge

diff --cc src/coreclr/src/jit/lowerxarch.cpp
Simple merge