Port IRBuilder::CreateVectorSplat
Check SIMD vector types
Add core::simd and define SIMD vector types
Add SIMD vector type tests
Remove trailing whitespace
Generate LLVM SIMD vector types
Move core::simd to core::unstable::simd
Show lint names
Remove #[cfg(notest)] and use #[cfg(not(test))] to cooincide with #[cfg(debug)]
libstd: convert chained ifs to a match in base64.
Fix typos
fix incorrect region code based on the old 'self

also removes unnecessary casts from the RcMut implementation
auto merge of #6214 : sanxiyn/rust/simd-2, r=graydon

At the moment this only includes type checking and there is no code generation support yet. I wanted to get the design reviewed first.

From discussion with @graydon at #5841, re-implemented as `#[simd]` attribute on structs.

Progressing towards #3499.
rename iter::iter_to_vec to iter::to_vec

it's silly to duplicate the namespace in the fn name
libstd: Remove mutable fields from fileinput and net_tcp
libstd: Remove mutable fields from flatpipes and io_util
libstd: Remove mutable fields from future and par
libstd: Start warning about mutable fields, now that they only exist in stage0
libcore: Remove mutable fields from rand.
libcore: Remove mutable fields from os and ptr