[PowerPC] Disable sanitizer test due to failures when using LLD

This test case fails due to different handling of weak items between
LLD and LD on PPC. The issue only occurs when the default linker is LLD
and the test case is run on a system where ASLR is enabled.

compiler-rt/test/asan/TestCases/Posix/no-fd.cpp

@@ -6,8 +6,9 @@
 
 // This test closes the 0, 1, and 2 file descriptors before an exec() and relies
 // on them remaining closed across an execve(). This is not the case on newer
-// versions of Android.
-// UNSUPPORTED: android
+// versions of Android. On PPC with ASLR turned on, this fails when linked with
+// lld - see https://bugs.llvm.org/show_bug.cgi?id=45076.
+// UNSUPPORTED: android, powerpc
 
 #include <assert.h>
 #include <stdio.h>