[dotest] Fix compiler version number comparison

[friss]

Summary

dotest's version comparision function is just a lexicographical compare
of the version strings. This is obviously wrong. This patch implements
a numerical comparision of the individual version components instead.

Python is not my language of choice, please suggest a better implementation!

[friss]

Use LooseVersion as suggested by Zachary

packages/Python/lldbsuite/test/lldbtest.py

def expectedCompilerVersion(self, compiler_version):
         """
         if (compiler_version is None):
             return True
         operator = str(compiler_version[0])
         version = compiler_version[1]
 
         if (version is None):
             return True
+
+        def compare_version_strings(v1, v2):
+            split1 = v1.split('.')
+            split2 = v2.split('.')
+            while len(split1) > len(split2):
+                split2.append("0")
+            while len(split2) > len(split1):
+                split1.append("0")
+
+            versions = zip(split1, split2)
+            for (subv1, subv2) in versions:
+                diff = int(subv1) - int(subv2)
+                if diff != 0:
+                    return diff
+
+            return 0
+
         if (operator == '>'):
-            return self.getCompilerVersion() > version
+            return compare_version_strings(self.getCompilerVersion(), version) > 0
         if (operator == '>=' or operator == '=>'):
-            return self.getCompilerVersion() >= version
+            return compare_version_strings(self.getCompilerVersion(), version) >= 0
         if (operator == '<'):
-            return self.getCompilerVersion() < version
+            return compare_version_strings(self.getCompilerVersion(), version) < 0
         if (operator == '<=' or operator == '=<'):
-            return self.getCompilerVersion() <= version
+            return compare_version_strings(self.getCompilerVersion(), version) <= 0
         if (operator == '!=' or operator == '!' or operator == 'not'):
             return str(version) not in str(self.getCompilerVersion())
         return str(version) in str(self.getCompilerVersion())
 
     def expectedCompiler(self, compilers):
         """Returns True iff any element of compilers is a sub-string of the current compiler."""
         if (compilers is None):
             return True