compiler: typing fixes for Interface_mtable_expression

Interface_mtable_expression::do_type computes a type that incorporates
Go type descriptors for the interface methods, whereas in order to
have strict type agreement with the mtable data, the interface method
fields need to be C function ptrs. Change the type recipe accordingly,
and then update Interface_mtable_expression::do_get_backend to compute
a revised backend type that uses the correct fcn types.

Change-Id: I2e5040debd6d32175e622bdf86c9e5cf4f30d54a
Reviewed-by: Ian Lance Taylor <>
2 files changed