get constification working for "this"

Creating release candidate rc2 from release_801 branch

llvm-svn: 363031

Creating release candidate rc1 from release_801 branch

llvm-svn: 360979

Creating release candidate final from release_710 branch

llvm-svn: 358242

Creating release candidate rc1 from release_710 branch

llvm-svn: 356991

Creating release candidate final from release_800 branch

llvm-svn: 356365

Creating release candidate rc5 from release_800 branch

llvm-svn: 355910

Creating release candidate rc4 from release_800 branch

llvm-svn: 355691

Creating release candidate rc3 from release_800 branch

llvm-svn: 355016

Creating release candidate rc2 from release_800 branch

llvm-svn: 353414