IDIOM 22: ignore UNSIGNED OVERFLOW when an operation sequence using constant operands indicates likely overflow.

Fixes for idapro 6.4;  allins.h seems to not be something one should include directly, include intel.h instead.

IDIOM 17: overflows of jump table offset computations should be UNKNOWNSIGN checks instead of UNSIGNED.

Detect more benign truncations in IDIOM 2 based on the original source of the truncated operand and its subsequent uses.

Begin the loop identification process with the data structures and fundamental methods of back edge discovery.

Expand IDIOM 3 to include subtraction of small immediate from condition code; add IDIOM 13 for all NEGATEDPTR references; increase MEDS propagation of POINTER types.

Benign underflow idioms 11 and 12; subtrahend is large constant, or both operands were obtained from zero-extended moves.

Build RTLs for dryrun lib opcodes; fix uninit vars and clean up code; start mul by large const idiom recognition.

Do not allow DEF signedness to become mixed due to propagation of USE operand signedness within an RTL.