Implement `:- pragma foreign_import_module(Lang, Module)', which tells

Estimated hours taken: 10

Implement `:- pragma foreign_import_module(Lang, Module)', which tells
the compiler that the foreign code in the module containing the
declaration uses `:- pragma export'ed procedures from module `Module'.
This information is needed for mmake to build things in the right order.
Currently programmers can hand code the required mmake rules, but
`mmc --make' will have no mechanism for doing this.

`:- pragma c_import_module(Module)' is a synonym for
`:- pragma foreign_import_module("C", Module)'.

compiler/prog_io_pragma.m:
	Parse the new pragmas.

compiler/prog_data.m:
compiler/foreign.m:
compiler/hlds_module.m:
compiler/mlds.m:
compiler/modules.m:
	Add the `:- pragma foreign_import_module' to the
	compiler's datastructures.

compiler/make_hlds.m:
	Insert `:- pragma foreign_import_module' declarations
	into the HLDS.

compiler/modules.m:
	Add the extra dependency information from
	`:- pragma foreign_import_module' declarations
	to the `.d' files.

compiler/llds.m:
compiler/foreign.m:
	Move some non-backend-specific types describing the foreign
	language interface from llds.m to foreign.m.

compiler/intermod.m:
	Write `:- pragma foreign_import_module' declarations
	to `.opt' files. XXX mmake doesn't support this properly yet.

compiler/mercury_compile.m:
compiler/foreign.m:
compiler/ml_code_gen.m:
compiler/ml_code_gen.m:
compiler/mlds_to_c.m:
compiler/mlds_to_csharp.m:
compiler/mlds_to_gcc.m:
compiler/mlds_to_mcpp.m:
	Convert `:- pragma foreign_import_module' to `#include'
	statements where appropriate depending on the target
	language.

compiler/*.m:
	Handle `:- pragma foreign_import_module'.
	Import foreign.m rather than llds.m for the foreign
	interface types.

doc/reference_manual.texi:
NEWS:
	Document the new pragmas.
	Minor fixes for the foreign code documentation.

tests/hard_coded/Mmakefile:
tests/hard_coded/foreign_import_module.m:
tests/hard_coded/foreign_import_module_2.m:
tests/hard_coded/foreign_import_module.exp:
	Test case.

compiler/prog_io_pragma.m

@@ -171,6 +171,41 @@ parse_pragma_type(ModuleName, "c_code", PragmaTerms,
 		    ErrorTerm)
 	).
 
+parse_pragma_type(_ModuleName, "c_import_module", PragmaTerms,
+		ErrorTerm, _VarSet, Result) :-
+	(
+		PragmaTerms = [ImportTerm],
+		sym_name_and_args(ImportTerm, Import, [])
+	->
+		Result = ok(pragma(foreign_import_module(c, Import)))	
+	;
+		Result = error("wrong number of arguments or invalid module name in `:- pragma c_import_module' declaration", 
+			ErrorTerm)
+	).
+
+parse_pragma_type(_ModuleName, "foreign_import_module", PragmaTerms,
+		ErrorTerm, _VarSet, Result) :-
+	(
+	    PragmaTerms = [LangTerm, ImportTerm],
+	    sym_name_and_args(ImportTerm, Import, [])
+	->
+	    ( parse_foreign_language(LangTerm, Language) ->
+		( Language = c ->
+		    Result = ok(pragma(
+		    	foreign_import_module(Language, Import)))
+		;
+		    Result = error("`:- pragma foreign_import_module' not yet supported for languages other than C", LangTerm)
+		)
+	    ;
+		Result = error("invalid foreign language in `:- pragma foreign_import_module' declaration",
+			LangTerm)
+	    )
+	;
+	    Result = error("wrong number of arguments or invalid module name in `:- pragma foreign_import_module' declaration", 
+			ErrorTerm)
+			
+	).
+
 :- pred parse_foreign_language(term, foreign_language).
 :- mode parse_foreign_language(in, out) is semidet.