[XRay][compiler-rt] Require build-in-tree and x86_64-linux.
The quiet-start.cc test currently fails for arm (and potentially other
platforms). This change limits it to x86_64-linux.
Follow-up to D35789.
// RUN: XRAY_OPTIONS="patch_premain=true verbosity=0" %run %t 2>&1 | \
// RUN: FileCheck %s --check-prefix QUIET
// RUN: XRAY_OPTIONS="" %run %t 2>&1 | FileCheck %s --check-prefix DEFAULT
+//
+// FIXME: Understand how to make this work on other platforms
+// REQUIRES: built-in-llvm-tree
+// REQRUIES: x86_64-linux
#include <iostream>
using namespace std;
