IWYU for llvm-config.h in llvm, additions.

See r331124 for how I made a list of files missing the include.
I then ran this Python script:

    for f in open('filelist.txt'):
        f = f.strip()
        fl = open(f).readlines()

        found = False
        for i in xrange(len(fl)):
            p = '#include "llvm/'
            if not fl[i].startswith(p):
                continue
            if fl[i][len(p):] > 'Config':
                fl.insert(i, '#include "llvm/Config/llvm-config.h"\n')
                found = True
                break
        if not found:
            print 'not found', f
        else:
            open(f, 'w').write(''.join(fl))

and then looked through everything with `svn diff | diffstat -l | xargs -n 1000 gvim -p`
and tried to fix include ordering and whatnot.

No intended behavior change.

llvm-svn: 331184
diff --git a/llvm/lib/Analysis/AliasSetTracker.cpp b/llvm/lib/Analysis/AliasSetTracker.cpp
index c88e0dd..6fac7dd 100644
--- a/llvm/lib/Analysis/AliasSetTracker.cpp
+++ b/llvm/lib/Analysis/AliasSetTracker.cpp
@@ -14,6 +14,7 @@
 #include "llvm/Analysis/AliasSetTracker.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/MemoryLocation.h"
+#include "llvm/Config/llvm-config.h"
 #include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DataLayout.h"