Add `--linker` option to pass flags to the linker
rustc: Suppress derived pattern-match-checking errors

typeck::check::_match wasn't suppressing derived errors properly.
Fixed it.
Adds '--print-link-args' that outputs linker arguments that would be used
core: Replace uses of 'drop' in task module with 'finally'. #5379
rustc: Change At to Managed and Uniq to Owned
librustc: Fix drop finalizer not running for newtype structs.
rustc / test: Fix error message
Change flags to -Z print-link-args and --link-args
I modified the doc of from_elem, from_fn, I think it returns an owned vector
char: fix unused import warning
iter: add a find function
deleted two tests intended to test RUST_CC_ZEAL, an apparently defunct flag for the cycle collector
remove (non-parsing) test related to impl d for d feature
this issue is a dup of another one that has a correct test case

this test case has rotted wrt modern syntax. fortunately, this issue
was a dup of another one, and that one still ICEs.
This test case is obsolete for two reasons

First, it refers to a feature (trait bounds on type parameters) that's
apparently no longer in the language. Second, if I understand the issue
correctly, it should never have been a "run-pass" test because it was
supposed to fail.
changed to impl trait for type stx
iter: add max and min functions
clear *everything* from the tmp directory

The .tmp files were missed before. I don't think there's a need to use
*.ext instead of just *.
Fix error messages harder
Got test cases to pass, after some major surgery