[PATCH] clang-check should ignore -no-integrated-as because certain drivers can't handle it

[scott douglass]

> r194968 (reviewed at http://llvm-reviews.chandlerc.com/D2039) has 
> changed the behaviour of clang-check w.r.t. -no-integrated-as argument:
> previously, it was silently ignored; now, it's used to create the 
> Compilation, and then ignored further down the flow.
> 
> r194992 had to XFAIL test/Tooling/multi-jobs.cpp on the grounds that 
> "MSVC targeted drivers (*-win32) are incapable of invoking external
assembler."
> These drivers cannot create the Compilation when -no-integrated-as 
> argument is present.
> 
> Our patch restores the original behaviour, that is, silently ignoring 
> -no- integrated-as. This allows to un-XFAIL test/Tooling/multi-jobs.cpp.
> 
> OK to commit?

Is clang-check the only use of
FixedCompilationDatabase::loadFromCommandLine()?

Do we know why Clang::Tooling/multi-jobs.cpp has '--no-integrated-as' in the
first place?