cmake: Clean up functions, string operations, regular expressions, etc.
Remove the inclusion of the external module `CMakeParseArguments`.
Function argument parsing became a first-class feature in CMake 3.5.
Delete the function `find_symbol_prefix`. It is no longer used.
Use variables instead of strings in string operations where possible.
Prevent CMake from getting confused by string values that might be
accidentally identical to unrelated keywords.
Clean up spurious `.*` sequences in regex matching operations.
Rephrase a comment.
4 files changed
