Add getenv() wrapper that works on multibyte environment variable.

On Windows, character encoding of multibyte environment variable varies
depending on settings. The only reliable way to handle it I think is to use
GetEnvironmentVariableW().

GetEnvironmentVariableW() works on wchar_t string, which is on Windows UTF16
string. That's not ideal because we use UTF-8 as the internal encoding in LLVM.
This patch defines a wrapper function which takes and returns UTF-8 string for
GetEnvironmentVariableW().

The wrapper function does not do any conversion and just forwards the argument
to getenv() on Unix.

Differential Revision: http://llvm-reviews.chandlerc.com/D1612

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190423 91177308-0d34-0410-b5e6-96231b3b80d8
Fix typo

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190424 91177308-0d34-0410-b5e6-96231b3b80d8
Teach ScalarEvolution about pointer address spaces

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190425 91177308-0d34-0410-b5e6-96231b3b80d8
Fix missing CHECK-LABELs

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190426 91177308-0d34-0410-b5e6-96231b3b80d8
Try to unbreak mingw32 buildbot.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190438 91177308-0d34-0410-b5e6-96231b3b80d8
Hoist section call out of loop.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190440 91177308-0d34-0410-b5e6-96231b3b80d8
Fix spacing
Add braces
Add braces
Teach loop-idiom about address space pointer sizes
Fix assertion failure when ptrtoint int size is larger

When the int was larger than the pointer size, the saved constant
offset would be the wrong type at the uses, resulting in this failure.

In the added test case for example, the sub i64 ended up with
i32 operands, which would then fail on its use in the icmp.
Add address space assertion to getCastOpcode
Spacing around operators
Irrelevant formatting change
Check address space in isCastable because why not
Add address space assertions in CreatePointerCast
Add tests that will hit CreatePointerCast assertion in one place
Disable CreatePointerCast assertion
Teach InlineCost about address spaces
Support different sized address space pointers in BasicAA