[LSAN] Attempt to fix the ppc64 build by excluding unsupported test

[vitalybuka]

Do you know why PPC is not supported?

[kstoimenov]

In D142561#4080438, @vitalybuka wrote:

Do you know why PPC is not supported?

From the error it looks like the signal doesn't happen and we exit with leak detection. My guess is that somehow mprotect doesn't cause a crash on PPC, but it does on x86.

compiler-rt/test/lsan/TestCases/Linux/leak_check_segv.cpp

 // Test that SIGSEGV during leak checking does not crash the process.
 // RUN: %clangxx_lsan -O1 %s -o %t && not %run %t 2>&1 | FileCheck %s
+// UNSUPPORTED: ppc
 #include <stdlib.h>
 #include <stdio.h>
 #include <sys/mman.h>
 #include <sanitizer/lsan_interface.h>
 
 char data[10 * 1024 * 1024];
 
 int main() {