This pull request fixes coverage mapping on GPU targets. 

- It adds an address space cast to the coverage mapping generation pass.
- It reads the profiled function names from the ELF directly. Reading it
from public globals was causing issues in cases where multiple
device-code object files are linked together.

[Offload] Use new error code handling mechanism

This removes the old ErrorCode-less error method and requires
every user to provide a concrete error code. All calls have been
updated.

In addition, for consistency with error messages elsewhere in LLVM, all
messages have been made to start lower case.

This pull request is the third part of an ongoing effort to extends PGO
instrumentation to GPU device code and depends on
https://github.com/llvm/llvm-project/pull/93365. This PR makes the
following changes:

- Allows PGO flags to be supplied to GPU targets
- Pulls version global from device
- Modifies `__llvm_write_custom_profile` and `lprofWriteDataImpl` to
allow the PGO version to be overridden

This pull request is the second part of an ongoing effort to extends PGO
instrumentation to GPU device code and depends on #76587. This PR makes
the following changes:

- Introduces `__llvm_write_custom_profile` to PGO compiler-rt library.
This is an external function that can be used to write profiles with
custom data to target-specific files.
- Adds `__llvm_write_custom_profile` as weak symbol to libomptarget so
that it can write the collected data to a profraw file.
- Adds `PGODump` debug flag and only displays dump when the
aforementioned flag is set

https://github.com/codespell-project/codespell

% `codespell
--ignore-words-list=archtype,hsa,identty,inout,iself,nd,te,ths,vertexes
--write-changes`

Exposed by -Warray-bounds:

In file included from
../../../../../../../llvm/offload/plugins-nextgen/common/src/GlobalHandler.cpp:252:

../../../../../../../llvm/llvm/include/llvm/ProfileData/InstrProfData.inc:109:1:
error: array index 4 is past the end of the array (that has type 'const
std::remove_const<const uint16_t>::type[4]' (aka 'const unsigned
short[4]')) [-Werror,-Warray-bounds]
109 | INSTR_PROF_DATA(const uint16_t, Int16ArrayTy,
NumValueSites[IPVK_Last+1], \
| ^ ~~~~~~~~~~~

../../../../../../../llvm/offload/plugins-nextgen/common/src/GlobalHandler.cpp:250:15:
note: expanded from macro 'INSTR_PROF_DATA'
250 | outs() << ProfData.Name << " "; \
      |               ^        ~~~~

../../../../../../../llvm/llvm/include/llvm/ProfileData/InstrProfData.inc:109:1:
note: array 'NumValueSites' declared here
109 | INSTR_PROF_DATA(const uint16_t, Int16ArrayTy,
NumValueSites[IPVK_Last+1], \
      | ^

../../../../../../../llvm/offload/plugins-nextgen/common/include/GlobalHandler.h:62:3:
note: expanded from macro 'INSTR_PROF_DATA'
   62 |   std::remove_const<Type>::type Name;

Avoid accessing out-of-bound data, but skip printing array data for now.
As there is no simple way to do this without hardcoding the
NumValueSites field.

---------

Co-authored-by: Ethan Luis McDonough <ethanluismcdonough@gmail.com>

We had three `utils::` namespaces, all with different "meaning" (host,
device, hsa_utils). We should, when we can, keep "include/Shared"
accessible from host and device, thus RefCountTy has been moved to a
separate header. `hsa_utils` was introduced to make `utils::` less
overloaded. And common functionality was de-duplicated, e.g.,
`utils::advance` and `utils::advanceVoidPtr` -> `utils:advancePtr`. Type
punning now checks for the size of the result to make sure it matches
the source type.

No functional change was intended.

This pull request is a revised version of #76587. This pull request
fixes some build issues that were present in the previous version of
this change.

> This pull request is the first part of an ongoing effort to extends
PGO instrumentation to GPU device code. This PR makes the following
changes:
>
> - Adds blank registration functions to device RTL
> - Gives PGO globals protected visibility when targeting a supported
GPU
> - Handles any addrspace casts for PGO calls
> - Implements PGO global extraction in GPU plugins (currently only
dumps info)
>
> These changes can be tested by supplying `-fprofile-instrument=clang`
while targeting a GPU.

This reverts commit 5fd2af38e461445c583d7ffc2fe23858966eee76. It caused build issues and broke the buildbot.

This pull request is the first part of an ongoing effort to extends PGO
instrumentation to GPU device code. This PR makes the following changes:

- Adds blank registration functions to device RTL
- Gives PGO globals protected visibility when targeting a supported GPU
- Handles any addrspace casts for PGO calls
- Implements PGO global extraction in GPU plugins (currently only dumps
info)

These changes can be tested by supplying `-fprofile-instrument=clang`
while targeting a GPU.