bpo-36876: Re-organize the c-analyzer tool code. (gh-16841)

This is partly a cleanup of the code. It also is preparation for getting the variables from the source (cross-platform) rather than from the symbols.

The change only touches the tool (and its tests).

Tools/c-analyzer/c_parser/source.py

@@ -1,34 +0,0 @@
-from . import preprocessor
-
-
-def iter_clean_lines(lines):
-    incomment = False
-    for line in lines:
-        # Deal with comments.
-        if incomment:
-            _, sep, line = line.partition('*/')
-            if sep:
-                incomment = False
-            continue
-        line, _, _ = line.partition('//')
-        line, sep, remainder = line.partition('/*')
-        if sep:
-            _, sep, after = remainder.partition('*/')
-            if not sep:
-                incomment = True
-                continue
-            line += ' ' + after
-
-        # Ignore blank lines and leading/trailing whitespace.
-        line = line.strip()
-        if not line:
-            continue
-
-        yield line
-
-
-def iter_lines(filename, *,
-               preprocess=preprocessor.run,
-               ):
-    content = preprocess(filename)
-    return iter(content.splitlines())