i965/disasm: Skip swizzle disassembly when using 3-src repctrl.
i965/disasm: Skip swizzle disassembly when using 3-src repctrl.

... since it's always .x, and also always print the subreg offset when
using repctrl.

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler