merging with Laurent's revision 55b074ea7255 (essentially ignoring all changes)

Add coment warning about incorrect implementation of the NE standard function.

merging with Laurent's patch.

Print correct error message when handling IL function calls.

Edit error message.

Add EXPT widen table.

Some stupid code cleanups.

Some code cleanups.

Clean up the code.

Fix error messages of il function calls - it now prints out location info of first parameter.

Clean code for printing errors in expressions.

Clean code for comparison operations & operators.

Cleaning up XORN, ANDN, and ORN operator code.

Cleaning up some code.

Add 'widen' tables for AND, OR and XOR operations.

Add MOD widening table, and some code clean-ups.

Re-organizing the code.

Change setting of deprecated_operation from fill to narrow_candidate_datatypes_c.
Expand widening tables for ADD, SUB, MUL and DIV.

Clarify some details in the comments.

Add check widening status for IL operator.
Fix check widening status for ST expression.

Fix remaining 'widen' tables.

Fix some 'widen' table entries.

Add a TODO comment.

Clean up code, and add support for 'safe' version of literals.

Bringing comment up to date.

Semantic verification of NOT operator.

Fix bug in building structured variables.

Delete unecessary copy_candidate_datatype_list() function.

Delete no longer needed copy_candidate_datatype_list() function.

Narrow IL lists twice, in order to handle JMP to labels before the JMP itself.

Do not allow duplicate values in candidate datatype list.

Handle JMP to labels preceding the JMP instruction itself.