gcc: GCC generates incorrect code for RDRAND/RDSEED intrinsics

Under certain circumstances, the ix86expandbuiltin function in i386.c in GNU Compiler Collection GCC version 4.6, 4.7, 4.8, 4.9, 5 before 5.5, and 6 before 6.4 will generate instruction sequences that clobber the status flag of the RDRAND and RDSEED intrinsics before it can be read, potentially...