* builtins.c (fold_builtin_fputs): Don't bother converting the
return type to integer_type_node, as we've already checked that
the result will be ignored.
* tree-eh.c (tree_could_trap_p): Add support for -ftrapv such
that signed addition, subtraction, multiplication, division,
remainder, negation and absolute value may potentially trap.
* fold-const.c (fold_ignored_result): New function to strip
non-side-effecting tree nodes from an expression whose result
is ignored.
(fold_convert): Call fold_ignored_result when casting a value
to VOID_TYPE.
(omit_one_operand): Call fold_ignored_result on the "omitted"
operand when building a COMPOUND_EXPR.
(pedantic_omit_one_operand): Likewise.
* tree.h (fold_ignored_result): Prototype here.
* tree-ssa-ccp.c (ccp_fold_builtin): Call fold_ignored_result
when we're going to ignore the result.
From-SVN: r84525
