X86: Correct vectorization cost model for v8f32->v8i8.

Fix the cost model to reflect the reality of our codegen.

rdar://16370633

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204880 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-cov: When reading strings in gcov data, skip leading zeros

It seems that gcov, when faced with a string that is apparently zero
length, just keeps reading words until it finds a length it likes
better. I'm not really sure why this is, but it's simple enough to
make llvm-cov follow suit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204881 91177308-0d34-0410-b5e6-96231b3b80d8
add 'requires asserts' to test that needs it

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204882 91177308-0d34-0410-b5e6-96231b3b80d8
Correctly propagates st_size.

This also finally removes a bogus call to AliasedSymbol.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204883 91177308-0d34-0410-b5e6-96231b3b80d8
[X86][Vectorizer Cost Model] Correct vectorization cost model for v2i64->v2f64
and v4i64->v4f64.

The new costs match what we did for SSE2 and reflect the reality of our codegen.

<rdar://problem/16381225>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204884 91177308-0d34-0410-b5e6-96231b3b80d8