Add workaround for buggy cpp on PowerPC

Description

The GCC C preprocessor has a bug on PowerPC architectures that makes it treat vector has a predefined macro (see https://gcc.gnu.org/bugzilla/show_bug.cgi?format=multiple&id=51654 for more details). This MR adds a workaround at configure time to deal with the bug.

News snippet

Added workaround for bug in GCC C preprocessor on PowerPC.

Checklist

• I have checked that my code follows the Octopus coding standards
• I have added tests for all the new features added in this request.