Merge pull request dotnet/coreclr#15657 from mikedn/fp-divmul-binary

Move FP DIV/MUL handling to genCodeForBinary

Commit migrated from https://github.com/dotnet/coreclr/commit/6517a3519ef721d50b6b52995ca89d09b46189a2

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

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

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