Revert "std: convert {vec,str}::to_owned to methods."

This fixes the strange random crashes in compile-fail tests.

This reverts commit 96cd61ad034cc9e88ab6a7845c3480dbc1ea62f3.

Conflicts:
	src/librustc/driver/driver.rs
	src/libstd/str.rs
	src/libsyntax/ext/quote.rs
std: get std::path tests to work again
Merge pull request #7129 from erickt/fix-std-path-tests

std: get std::path tests to work again
Use DIBuilder in debuginfo
Made the while DebugContext mutable, not just created_* hashes
Disabled create_arg
Move "return" basic block after all other function blocks.
Debug loc for local var declarations
Removed extraneous string allocations.
Misc refactoring.
Fixed compile warnings.
Fixed whitespace "errors".
Fixed remaining issues to pass debug-test/* tests.
Made debugger scripts source line insensitive.
Converted vec::map to member.
Made unimplemented debuginfo a note rather than a compiler error.
Refactoring and tidy warnings cleanup.