Make guessing the target an info instead of a warning

Having this as a warning makes IDEs to go to the Makefile where the
warning was issued as if an error occurred, which is rather annoying for
something is really normal. An info is enough to let the user now how
the target was guessed.
Merge pull request #1826 from leandro-lucarella-sociomantic/cpu-warn-to-info-d1

[trivial D1] Make guessing the target an info instead of a warning
Merge pull request #1820 from WalterBright/refactorApply

make use of Statement::apply()
Merge pull request #1827 from WalterBright/fix9863

fix Issue 9863 - Incorrect generation of SAHF instruction on 64 bits
Merge pull request #1823 from WalterBright/fix9720

fix Issue 9720 - OSX wrong code with -O Illegal instruction
Merge pull request #1831 from rainers/cv8_void_array

CodeView debug info: translate void[N] to ubyte[N]