Misc Decimal optimizations
Misc Decimal optimizations

Signed-off-by: dotnet-bot <03c4cb6107ae99956a7681f2c97ff7104809a2bd@microsoft.com>
Signed-off-by: dotnet-bot-corefx-mirror <03c4cb6107ae99956a7681f2c97ff7104809a2bd@microsoft.com>

ptoonen/corefx,Jiayili1/corefx,shimingsg/corefx,ericstj/corefx,ptoonen/corefx,ptoonen/corefx,BrennanConroy/corefx,Ermiar/corefx,shimingsg/corefx,Jiayili1/corefx,ViktorHofer/corefx,ericstj/corefx,wtgodbe/corefx,Jiayili1/corefx,mmitche/corefx,Ermiar/corefx,zhenlan/corefx,ViktorHofer/corefx,BrennanConroy/corefx,mmitche/corefx,Jiayili1/corefx,ericstj/corefx,shimingsg/corefx,shimingsg/corefx,ravimeda/corefx,wtgodbe/corefx,Ermiar/corefx,mmitche/corefx,wtgodbe/corefx,ViktorHofer/corefx,ptoonen/corefx,Jiayili1/corefx,zhenlan/corefx,ptoonen/corefx,ericstj/corefx,zhenlan/corefx,Jiayili1/corefx,ViktorHofer/corefx,mmitche/corefx,zhenlan/corefx,zhenlan/corefx,BrennanConroy/corefx,ericstj/corefx,ravimeda/corefx,shimingsg/corefx,mmitche/corefx,ericstj/corefx,ViktorHofer/corefx,ViktorHofer/corefx,wtgodbe/corefx,ravimeda/corefx,ravimeda/corefx,Jiayili1/corefx,ravimeda/corefx,ericstj/corefx,Ermiar/corefx,shimingsg/corefx,wtgodbe/corefx,wtgodbe/corefx,Ermiar/corefx,Ermiar/corefx,shimingsg/corefx,ViktorHofer/corefx,ptoonen/corefx,mmitche/corefx,wtgodbe/corefx,mmitche/corefx,ravimeda/corefx,ravimeda/corefx,ptoonen/corefx,zhenlan/corefx,Ermiar/corefx,zhenlan/corefx