Remove the no_sanitize attribute in favor of sanitize

This removes the #[no_sanitize] attribute, which was behind an unstable
feature named no_sanitize. Instead, we introduce the sanitize attribute
which is more powerful and allows to be extended in the future (instead
of just focusing on turning sanitizers off).

This also makes sanitize(kernel_address = ..) attribute work with
-Zsanitize=address

To do it the same as how clang disables address sanitizer, we now
disable ASAN on sanitize(kernel_address = "off") and KASAN on
sanitize(address = "off").

The same was added to clang in https://reviews.llvm.org/D44981.

Author: 1c3t3a

src/sanitizers.md

@@ -45,7 +45,7 @@ implementation:
    [marked][sanitizer-attribute] with appropriate LLVM attribute:
    `SanitizeAddress`, `SanitizeHWAddress`, `SanitizeMemory`, or
    `SanitizeThread`. By default all functions are instrumented, but this
-   behaviour can be changed with `#[no_sanitize(...)]`.
+   behaviour can be changed with `#[sanitize(xyz = "on|off")]`.
 
 *  The decision whether to perform instrumentation or not is possible only at a
    function granularity. In the cases were those decision differ between