2007-08-16  Hristian Kirtchev  <kirtchev@adacore.com>
	    Bob Duff  <duff@adacore.com>
	    Nicolas Setton  <setton@adacore.com>

	* sem_res.adb (Comes_From_Predefined_Lib_Unit): New.
	(Resolve): Alphabetize local variables. Add new variable From_Lib. When
	the statement which is being resolved comes from a predefined library
	unit, all non-predefined library interpretations are skipped.
	(Resolve_Op_Concat): If string concatenation was folded in the parser,
	but the "&" is user defined, give an error, because the folding would
	be wrong.

	* sinfo.ads, sinfo.adb (Is_Folded_In_Parser): New flag to indicate that
	the parser has folded a long sequence of concatenations of string
	literals.

	* trans.c (Handled_Sequence_Of_Statements_to_gnu): Mark "JMPBUF_SAVE"
	and "JMP_BUF" variables as artificial.
	(N_String_Literal): Do not use alloca for very long string literals. Use
	xmalloc/free instead. Otherwise the stack might overflow.

	* utils.c (init_gigi_decls): Mark "JMPBUF_T" type as created by the
	compiler.

From-SVN: r127550