Use absolute clang-cl path instead

git-svn-id: http://address-sanitizer.googlecode.com/svn/trunk@1859 3c3640eb-14a6-2bb8-0b94-e9e73afe33f5
Replace more slashes with backslashes

git-svn-id: http://address-sanitizer.googlecode.com/svn/trunk@1860 3c3640eb-14a6-2bb8-0b94-e9e73afe33f5
Disable building the ASan runtime with clang-cl as the latter doesn't support wildcarded source file lists

git-svn-id: http://address-sanitizer.googlecode.com/svn/trunk@1861 3c3640eb-14a6-2bb8-0b94-e9e73afe33f5