generator: support fixed size lists in var-sized structs

generator: support fixed size lists in var-sized structs

V2: patch revised according to suggestions from Ran Benita:
* removed blanks before an after parentheses of function-calls or tuples
* replaced if by elif in "if field.type.is_list". ( this fixes old code )

Message-ID: <540B4D17.1080908@DemoRecorder.com>
Patch-Thread-Subject: [Xcb] xinput:QueryDeviceState: full-support: generator and xml-changes
Patch-Set: QueryDeviceState
Patch-Number: libxcb 1/3
Patch-Version: V2
Signed-off-by: Christian Linhart <chris@DemoRecorder.com>
Reviewed-By: Ran Benita <ran234@gmail.com>