Revert "Masked Vector Load and Store Intrinsics."

This reverts commit r222632 (and follow-up r222636), which caused a host
of LNT failures on an internal bot.  I'll respond to the commit on the
list with a reproduction of one of the failures.

Conflicts:
	lib/Target/X86/X86TargetTransformInfo.cpp

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222936 91177308-0d34-0410-b5e6-96231b3b80d8
Use std::map<K, V> rather than std::map<K, std::unique_ptr<V>>

Pointers and references to map elements are never invalidated (except on
removal, which isn't used here) so there's no need for the indirection
unless there's polymorphism at work.

A little const correctness had to be fixed, since the indirection
allowed some benign const violations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222937 91177308-0d34-0410-b5e6-96231b3b80d8
Push unique_ptr a bit further through some APIs and simplify some cleanup

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222938 91177308-0d34-0410-b5e6-96231b3b80d8
Revert "Use std::map<K, V> rather than std::map<K, std::unique_ptr<V>>"

Seems libstdc++ on some buildbots is lacking std::map::emplace, which is
weird... reverting while I look into it.

This reverts commit r222937.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222939 91177308-0d34-0410-b5e6-96231b3b80d8
Reapply "Use std::map<K, V> rather than std::map<K, std::unique_ptr<V>>""

Just avoid using std::map::emplace since it's not implemented in
libstdc++ 4.7.

Reapplies r222937, reverted in r222939.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222940 91177308-0d34-0410-b5e6-96231b3b80d8