style: fix amd license and style issues

Change-Id: I26136fb49f743c4a597f8021cfd27f78897267b5
Reviewed-on: https://gem5-review.googlesource.com/10463
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>

gpu-compute: mark functions with override if replacing virtual

The clang compiler is more stringent than the recent versions of
GCC when dealing with overrides. This changeset adds the specifier
to the methods which need it to silence the compiler.

hsail,gpu-compute: fixes to appease clang++

fixes to appease clang++. tested on:

Ubuntu clang version 3.5.0-4ubuntu2~trusty2
(tags/RELEASE_350/final) (based on LLVM 3.5.0)

Ubuntu clang version 3.6.0-2ubuntu1~trusty1
(tags/RELEASE_360/final) (based on LLVM 3.6.0)

the fixes address the following five issues:

1) the exec continuations in gpu_static_inst.hh were marked
as protected when they should be public. here we mark
them as public

2) the Abs instruction uses std::abs() in its execute method.
because Abs is templated, it can also operate on U32 and U64,
types, which cause Abs::execute() to pass uint32_t and uint64_t
types to std::abs() respectively. this triggers a warning
because std::abs() has no effect in this case. to rememdy this
we add template specialization for the execute() method of Abs
when its template paramter is U32 or U64.

3) Some potocols that utilize the code in cprintf.hh were missing
includes to BoolVec.hh, which defines operator<< for the BoolVec
type. This would cause issues when the generated code would try
to pass a BoolVec type to a method in cprintf.hh that used
operator<< on an instance of a BoolVec.

4) Surprise, clang doesn't like it when you clobber all the bits
in a newly allocated object. I.e., this code:

tlb = new GpuTlbEntry\[size\];
std::memset(tlb, 0, sizeof(GpuTlbEntry) \* size);

Let's use std::vector to track the TLB entries in the GpuTlb now...

5) There were a few variables used only in DPRINTFs, so we mark them
with M5_VAR_USED.

gpu-compute, hsail: pass GPUDynInstPtr to getRegisterIndex()

for HSAIL an operand's indices into the register files may be calculated
trivially, because the operands are always read from a register file, or are
an immediate.

for machine ISA, however, an op selector may specify special registers, or
may specify special SGPRs with an alias op selector value. the location of
some of the special registers values are dependent on the size of the RF
in some cases. here we add a way for the underlying getRegisterIndex()
method to know about the size of the RFs, so that it may find the relative
positions of the special register values.

gpu-compute, hsail: make the PC a byte address, not an instruction index

currently the PC is incremented on an instruction granularity, and not as an
instruction's byte address. machine ISA instructions assume the PC is a byte
address, and is incremented accordingly. here we make the GPU model, and the
HSAIL instructions treat the PC as a byte address as well.

gpu-compute: remove inst enums and use bit flag for attributes

this patch removes the GPUStaticInst enums that were defined in GPU.py.
instead, a simple set of attribute flags that can be set in the base
instruction class are used. this will help unify the attributes of HSAIL
and machine ISA instructions within the model itself.

because the static instrution now carries the attributes, a GPUDynInst
must carry a pointer to a valid GPUStaticInst so a new static kernel launch
instruction is added, which carries the attributes needed to perform a
the kernel launch.

gpu-compute: move disassemle() implementation to GPUStaticInst

gpu-compute, arch: add some methods to the base inst classes for ISA support

gpu-compute: AMD's baseline GPU model