CalcSpillWeights: Hack to prevent x87 nonsense

This gross hack forces `hweight` into memory, preventing hidden
precision from making `1 > 1` occasionally equal `true`.

<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206765 91177308-0d34-0410-b5e6-96231b3b80d8
Reapply "blockfreq: Rewrite BlockFrequencyInfoImpl"

This reverts commit r206707, reapplying r206704.  The preceding commit
to CalcSpillWeights should have sorted out the failing buildbots.

<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206766 91177308-0d34-0410-b5e6-96231b3b80d8
Object: iterator_range accessors for ObjectImage symbols and sections.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206767 91177308-0d34-0410-b5e6-96231b3b80d8
Tidy up. Remove extraneous typedef.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206768 91177308-0d34-0410-b5e6-96231b3b80d8
[rtdyld,c++11] Range'ify symbol table walking.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206769 91177308-0d34-0410-b5e6-96231b3b80d8
blockfreq: Some cleanup of UnsignedFloat

Change `PositiveFloat` to `UnsignedFloat`, and fix some of the comments
to indicate that it's disappearing eventually.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206771 91177308-0d34-0410-b5e6-96231b3b80d8
Fix unnecessary line break

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206772 91177308-0d34-0410-b5e6-96231b3b80d8