[C++11] Replacing Scope iterators using_directives_begin() and using_directives_end() with iterator_range using_directives(). Updating all of the usages of the iterators with range-based for loops, and removing the no-longer-needed iterator versions.
R600/SI: Add generic checks to SIInstrInfo::verifyInstruction()

Added checks for number of operands and operand register classes.

Tested-by: Michel Dänzer <michel.daenzer@amd.com>
R600/SI: Use correct dest register class for V_READFIRSTLANE_B32

This instructions writes to an 32-bit SGPR.  This change required adding
the 32-bit VCC_LO and VCC_HI registers, because the full VCC register
is 64 bits.

This fixes verifier errors on several of the indirect addressing piglit
tests.

Tested-by: Michel Dänzer <michel.daenzer@amd.com>
R600/SI: Fix implementation of isInlineConstant() used by the verifier

The type of the immediates should not matter as long as the encoding is
equivalent to the encoding of one of the legal inline constants.

Tested-by: Michel Dänzer <michel.daenzer@amd.com>