Use MSVC intrinsics for lg_floor
Use MSVC intrinsics for lg_floor

When using MSVC make use of its intrinsic functions (supported on
x86, amd64 & ARM) for lg_floor.

Dmitry-Me/jemalloc,kmiku7/jemalloc,wespelee/jemalloc,dxq-git/jemalloc,Snaipe/jemalloc,tempbottle/jemalloc,8l/jemalloc,wespelee/jemalloc,geekboxzone/mmallow_external_jemalloc,wqfish/jemalloc,lilothar/jemalloc,dxq-git/jemalloc,yy-nm/jemalloc,cpeterso/jemalloc,kmiku7/jemalloc,leebaok/jemalloc-4.2.1-readcode,flyfeifan/jemalloc,shekkbuilder/jemalloc,shekkbuilder/jemalloc,dxq-git/jemalloc,wfxiang08/jemalloc,8l/jemalloc,leebaok/jemalloc-4.2.1-readcode,garoose/jemalloc,CMRemix/android_external_jemalloc,Snaipe/jemalloc,awreece/jemalloc,shekkbuilder/jemalloc,yy-nm/jemalloc,leebaok/jemalloc-4.2.1-readcode,AndroidExternal/jemalloc,TeamExodus/external_jemalloc,jemalloc/jemalloc-cmake,TeamExodus/external_jemalloc,kmiku7/jemalloc,flyfeifan/jemalloc,geekboxzone/mmallow_external_jemalloc,Dmitry-Me/jemalloc,CMRemix/android_external_jemalloc,yy-nm/jemalloc,lilothar/jemalloc,flyfeifan/jemalloc,ahmetmircik/jemalloc,CMRemix/android_external_jemalloc,AndroidExternal/jemalloc,8l/jemalloc,CMRemix/android_external_jemalloc,vashstorm/jemalloc,wqfish/jemalloc,cpeterso/jemalloc,awreece/jemalloc,garoose/jemalloc,jemalloc/jemalloc-cmake,TeamExodus/external_jemalloc,jemalloc/jemalloc-cmake,tempbottle/jemalloc,wqfish/jemalloc,wqfish/jemalloc,glandium/jemalloc,garoose/jemalloc,ahmetmircik/jemalloc,AndroidExternal/jemalloc,awreece/jemalloc,8l/jemalloc,lvfeng1130/jemalloc,awreece/jemalloc,cpeterso/jemalloc,glandium/jemalloc,wfxiang08/jemalloc,tempbottle/jemalloc,lvfeng1130/jemalloc,ahmetmircik/jemalloc,lvfeng1130/jemalloc,AndroidExternal/jemalloc,glandium/jemalloc,yy-nm/jemalloc,ahmetmircik/jemalloc,VRToxin/android_external_jemalloc,dxq-git/jemalloc,Dmitry-Me/jemalloc,cpeterso/jemalloc,wespelee/jemalloc,lilothar/jemalloc,wqfish/jemalloc,TeamExodus/external_jemalloc,flyfeifan/jemalloc,wfxiang08/jemalloc,VRToxin/android_external_jemalloc,lvfeng1130/jemalloc,shekkbuilder/jemalloc,jemalloc/jemalloc-cmake,Snaipe/jemalloc,Dmitry-Me/jemalloc,geekboxzone/mmallow_external_jemalloc,lilothar/jemalloc,vashstorm/jemalloc,glandium/jemalloc,wfxiang08/jemalloc,vashstorm/jemalloc,VRToxin/android_external_jemalloc,VRToxin/android_external_jemalloc,garoose/jemalloc,Snaipe/jemalloc,leebaok/jemalloc-4.2.1-readcode,wespelee/jemalloc,geekboxzone/mmallow_external_jemalloc,kmiku7/jemalloc,tempbottle/jemalloc,vashstorm/jemalloc