tree fe2a0c3d3a8b66f0282ef93a379d5eca01f38a4b
parent 5708c18904304ed4e39abed8131fcad5e2fc0896
author John McCall <rjmccall@apple.com> 1350440917 +0000
committer John McCall <rjmccall@apple.com> 1350440917 +0000

At -O0, prefer objc_storeStrong with a null new value to the
combination of a load+objc_release;  this is generally better
for tools that try to track why values are retained and
released.  Also use objc_storeStrong when copying a block
(again, only at -O0), which requires us to do a preliminary
store of null in order to compensate for objc_storeStrong's
assign semantics.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@166085 91177308-0d34-0410-b5e6-96231b3b80d8