rustc: Remove deprecated flags

This commit removes a number of deprecated flags from the compiler:

* opt-level => -C opt-level
* debuginfo => -C debuginfo
* print-crate-name => --print crate-name
* print-file-name => --print file-names
* no-trans => -Z no-trans
* no-analysis => -Z no-analysis
* parse-only => -Z parse-only
* dep-info => --emit dep-info

This commit also moves the --pretty flag behind `-Z unstable-options` as the
pretty printer will likely not be stable for 1.0

cc #19051

src/test/debuginfo/limited-debuginfo.rs

@@ -12,7 +12,7 @@
 
 // ignore-lldb
 
-// compile-flags:--debuginfo=1
+// compile-flags:-C debuginfo=1
 
 // Make sure functions have proper names
 // gdb-command:info functions