meson: Update min clang version to 9

__builtin_FILE and __builtin_LINE are first defined in clang 9. With
clang of any version less than that we have the following compilation
errors:

../../include/libcamera/base/log.h:94:27: error: use of undeclared identifier '__builtin_FILE'
                        const char *fileName = __builtin_FILE(),
                                               ^
../../include/libcamera/base/log.h:95:24: error: use of undeclared identifier '__builtin_LINE'
                        unsigned int line = __builtin_LINE()) const;
                                            ^
../../include/libcamera/base/log.h:99:26: error: use of undeclared identifier '__builtin_FILE'
                const char *fileName = __builtin_FILE(),
                                       ^
../../include/libcamera/base/log.h:100:23: error: use of undeclared identifier '__builtin_LINE'
                unsigned int line = __builtin_LINE());

Enforce clang version of at least 9 in the main meson file.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

0 files changed, 0 insertions, 0 deletions