rustc: Alias fix part 2 -- Check that the aliasness of function parameters matches. Add a test case.

rustc: Alias fix part 1 -- Separate out AST modes from typechecker modes, and introduce an "either value or alias" mode

rustc: Replace our homebrew list of passes with the standard function and module passes, along with the TargetData passes.

rustllvm: Add a function to add the standard function passes to a module; change uses of bool in LLVMAddStandardModulePasses() to LLVMBool

(Have fun mergining your stuff with this.)

rustc: For stack local derived tydescs, allocate the root tydesc separately from the parameter tydescs. This allows SROA, and consequently inlining, to work.