Since librustc and the fuzzer depend on rustllvm, build them
like rustc, linking to libraries in lib instead of lib/rustc/$(target)

Make tests and perf work again. Correctly get the host triple in rustc. Add
some FIXMEs about transitional code that needs to be removed.

Each stage is organized more according to Unix standards and to
accommodate multiple target architectures.

stageN/
  bin - rustc lives here
  lib - libraries that rustc needs
  lib/rustc/$(target_triple/ - target libraries

This is causing errors on my windows install

Issue #667

Issue #435

Issue #667

Issue #667

Issue #667

Other restrictions on pinned kinds happened to fix this

Closes #985

Vectors of pinned kinds can't be safe because most interesting uses of vector
perform copies

This reverts commit a034f871.

Conflicts:

	src/comp/middle/check_alt.rs
	src/comp/middle/trans_alt.rs
	src/comp/syntax/ast.rs
	src/comp/syntax/ast_util.rs
	src/comp/syntax/fold.rs
	src/comp/syntax/print/pprust.rs

Conflicts:

	src/comp/middle/trans_alt.rs