reverse of the "Identifiers can start and/or contain '.'"

reverse of the "Identifiers can start and/or contain '.'"

    - Identifiers can start and/or contain '.' in PARSE_FLAG_ASM_FILE
    - Move all GAS directives under TOK_ASMDIR prefix

    This patches breaks compilation of the tccboot (linux 2.4.26
    kernel). A test.S which fails with this patches:

    #define SRC(y...) \
    9999: y; \
    .section __ex_table, "a"; \
    .long 9999b, 6001f<---->; \
    .previous

    SRC(1:<>movw (%esi), %bx<------>)
    // 029-test.S:7: error: macro 'SRC' used with too many args