This patch changes code generation procedures add_code_header,
add_code_footer, and several other language-specific code generation
functions into policies.
gdb/ChangeLog:
* compile/compile-c-support.c (add_code_header, add_code_footer):
Move into policy class.
(c_push_user_expression, pop_user_expression_nop)
(c_add_code_header, c_add_code_footer, c_add_input): New policy class.
(compile_program): New host class.
(c_compile_program): New typedef.
(c_compute_porgram): Use c_compile_program.
ad3a68e9b9