Python: Copy Python extractor to codeql repo

python/extractor/tests/parser/comprehensions.py

@@ -0,0 +1,57 @@
+(a
+    for b in c
+        if d
+        if e
+    for f in g
+        if h
+        if i
+)
+
+(a1 for b1 in c1)
+
+(a2 for b2 in c2 if d2)
+
+[k 
+    for l in m
+        if n
+        if o
+    for p in q
+        if r
+        if s
+]
+
+[k1 for l1 in m1]
+
+[k2 for l2 in m2 if n2]
+
+{p
+    for q in r
+        if s
+        if t
+    for u in v
+        if w
+        if x
+}
+
+{p1 for q1 in r1}
+
+{p2 for q2 in r2 if s2}
+
+    
+{k3: v3
+    for l3 in m3
+        if n3
+        if o3
+    for p3 in q3
+        if r3
+        if s3
+}
+
+{k4: v4 for l4 in m4}
+
+{k5: v5 for l5 in m5 if n5}
+
+# Special case for generator expressions inside calls
+t = tuple(x for y in z)
+
+[(  t,  ) for v in w]