Enable Intel oneAPI DPC++/C++ compiler build (#16587)
Last week I fixed error #16484 found when trying to build onnxruntime
with the icpx compiler. Another thing I found out is that icpx uses
-ffast-math flag by default. You can check it by running the compiler
with -v flag like following:
```bash
# Setup the environment
. /opt/intel/oneapi/setvars.sh
# Compile any file to see all the implicit flags
icpx -v main.cpp
```
This leads to a bunch of warnings during the build like:
```bash
In file included from /mnt/f/wsl_home/onnxruntime/onnxruntime/test/providers/cpu/tensor/upsample_op_test.cc:5:
In file included from /mnt/f/wsl_home/onnxruntime/onnxruntime/test/providers/provider_test_utils.h:6:
In file included from /mnt/f/wsl_home/onnxruntime/onnxruntime/test/providers/checkers.h:10:
In file included from /mnt/f/wsl_home/onnxruntime/onnxruntime/core/util/math_cpuonly.h:68:
In file included from /mnt/f/wsl_home/onnxruntime/build/Linux/RelWithDebInfo/_deps/eigen-src/Eigen/Core:172:
/mnt/f/wsl_home/onnxruntime/build/Linux/RelWithDebInfo/_deps/eigen-src/Eigen/src/Core/MathFunctions.h:1019:12: warning: comparison with NaN always evaluates to false in fast floating point modes [-Wtautological-constant-compare]
return isnan EIGEN_NOT_A_MACRO (x);
^~~~~~~~~~~~~~~~~~~~~~~~~~~
```
And some tests are failing as well, usually with infinities involved. To
list a few:
```bash
# ...
1: [ FAILED ] IsInfTest.test_isinf_float
1: [ FAILED ] IsInfTest.test_isinf_double
1: [ FAILED ] IsInfTest.test_isinf_positive_float
1: [ FAILED ] IsInfTest.test_isinf_positive_double
1: [ FAILED ] IsInfTest.test_isinf_negative_float
1: [ FAILED ] IsInfTest.test_isinf_negative_double
1: [ FAILED ] IsNaNOpTest.IsNaNFloat
1: [ FAILED ] IsNaNOpTest.IsNaNDouble
# ...
```
This PR adds a quick global check for the IntelLLVM compiler, as in the
way its name is reported by CMake and then, depending on the compiler
driver, sets either MSVC-like or GCC-like switch to disable fast-maths.
Probably a bit cleaner solution would be to use
```target_compile_options(${TARGET} PRIVATE MEOW)``` instead of a
global-wide ```set(CMAKE_CXX_FLAGS MEOW)```, but then we'd be required
to add it to all the individual targets and execution providers and this
will lead to a lot of code duplication.
