[lldb][AArch64] Add MTE CPU feature test predicate

[DavidSpickett]

Summary

Change the logic slightly so that the feature can
be anywhere in the list.

[DavidSpickett]

I think we both have something like this in our changes. Yours will probably land sooner but here it is anyway.

[omjavaid]

This is accepted with a caveat above.

lldb/packages/Python/lldbsuite/test/lldbtest.py

1288

On AArch64 targets CPU features in cpuinfo file are written as Features while on x86 they are written as flags.

So Either we change the function name to reflect it can only be used for AArch64 or keep the previous logic to make it architecture independent.

[DavidSpickett]

Rename to be AArch64 specific.

[DavidSpickett]

Rebase

[DavidSpickett]

This is now redundant since Omair landed his changes.

lldb/packages/Python/lldbsuite/test/lldbtest.py

class Base(unittest2.TestCase):
 
     def isPPC64le(self):
         """Returns true if the architecture is PPC64LE."""
         arch = self.getArchitecture()
         if re.match("powerpc64le", arch):
             return True
         return False
 
-    def isAArch64SVE(self):
+    def hasAArch64LinuxCPUFeature(self, feature):
         triple = self.dbg.GetSelectedPlatform().GetTriple()
 
         # TODO other platforms, please implement this function
         if not re.match(".*-.*-linux", triple):
             return False
 
         # Need to do something different for non-Linux/Android targets
         cpuinfo_path = self.getBuildArtifact("cpuinfo")
         if configuration.lldb_platform_name:
             self.runCmd('platform get-file "/proc/cpuinfo" ' + cpuinfo_path)
         else:
             cpuinfo_path = "/proc/cpuinfo"
 
-        try:
-            f = open(cpuinfo_path, 'r')
-            cpuinfo = f.read()
-            f.close()
-        except:
+        with open(cpuinfo_path, 'r') as f:
+            for line in f.readlines():
+                if line.startswith("Features"):
+                    features = line.split(':')[1].split()
+                    return feature in features
             return False
 
-        return " sve " in cpuinfo
+    def isAArch64SVE(self):
+        return self.hasAArch64LinuxCPUFeature("sve")
+
+    def isAArch64MTE(self):
+        return self.hasAArch64LinuxCPUFeature("mte")
 
     def hasLinuxVmFlags(self):
         """ Check that the target machine has "VmFlags" lines in
         its /proc/{pid}/smaps files."""
 
         triple = self.dbg.GetSelectedPlatform().GetTriple()
         if not re.match(".*-.*-linux", triple):
             return False