stdlib: Add tests for PyStats's Vector and fix bugs

The big thing missing from the Vector stats was that each position in
the vector could have it's own unique id (a str, float, or int) and each
position in the vector can have its own description. Therefore, to add
this the Vector is represented as a dictionary mapping the unique ID to
a Pystat Scaler (whcih can have it's own unique description.

Change-Id: I3a8634f43298f6491300cf5a4f9d25dee8101808

src/python/m5/stats/gem5stats.py

@@ -183,29 +183,44 @@ def __get_distribution(statistic: _m5.stats.DistInfo) -> Distribution:
 
 
 def __get_vector(statistic: _m5.stats.VectorInfo) -> Vector:
-    to_add = dict()
+    vec: Dict[Union[str, int, float], Scalar] = {}
+
 
     for index in range(statistic.size):
         # All the values in a Vector are Scalar values
         value = statistic.value[index]
-        unit = statistic.unit
-        description = statistic.subdescs[index]
-        # ScalarInfo uses the C++ `double`.
-        datatype = StorageType["f64"]
+        assert isinstance(value, float) or isinstance(value, int)
 
         # Sometimes elements within a vector are defined by their name. Other
         # times they have no name. When a name is not available, we name the
         # stat the index value.
-        if str(statistic.subnames[index]):
-            index_string = str(statistic.subnames[index])
+        if len(statistic.subnames) > index and statistic.subnames[index]:
+            index_subname = str(statistic.subnames[index])
+            if index_subname.isdigit():
+                index_subname = int(index_subname)
+            elif index_subname.isnumeric():
+                index_subname = float(index_subname)
         else:
-            index_string = str(index)
+            index_subname = index
 
-        to_add[index_string] = Scalar(
-            value=value, unit=unit, description=description, datatype=datatype
+        index_subdesc = None
+        if len(statistic.subdescs) > index and statistic.subdescs[index]:
+            index_subdesc = str(statistic.subdescs[index])
+        else:
+            index_subdesc = statistic.desc
+
+        vec[index_subname] = Scalar(
+            value=value,
+            unit=statistic.unit,
+            description=index_subdesc,
+            datatype=StorageType["f64"],
         )
 
-    return Vector(scalar_map=to_add)
+    return Vector(
+        vec,
+        type="Vector",
+        description=statistic.desc,
+    )
 
 
 def _prepare_stats(group: _m5.stats.Group):