Detect cmd.exe special status code 9009 that indicates "command not
found" condition. Crash the process if "command not found" detected when
CMDSTAT was not specified.
EXECUTE_COMMAND_LINE() without CMDSTAT initiated termination in runtime
if the command returned non-zero status code. For example,
EXECUTE_COMMAND_LINE('false') on Linux would cause "fatal Fortran
runtime error... : Command line execution failed with exit code: 1."
This is too strict: EXECUTE_COMMAND_LINE() successfully called 'false',
it's just 'false' happened to return non-zero status code. ifx and
gfortran don't initiate termination in such case. Changed
EXECUTE_COMMAND_LINE() implementation to behave in similar fashion.
Also during testing discovered that when the output of the program that
uses EXECUTE_COMMAND_LINE(... WAIT=.false.) is piped to a file, the
resulting file has duplicated output lines. This was because fork()
command also ends up duplicating parent's buffered output to the child.
Added flush of all units and C stdio before calling fork().
We compile our monorepo with `/D_MBCS` and flang-rt compilation breaks
as it explicitly uses `wchar_t` (i. e. not TCHAR).
Use STARTUPINFOW / CreateProcessW method explicitly to make the code
work disregarding global settings.
Mostly mechanical changes in preparation of extracting the Flang-RT
"subproject" in #110217. This PR intends to only move pre-existing files
to the new folder structure, with no behavioral change. Common files
(headers, testing, cmake) shared by Flang-RT and Flang remain in
`flang/`.
Some cosmetic changes and files paths were necessary:
* Relative paths to the new path for the source files and
`add_subdirectory`.
* Add the new location's include directory to `include_directories`
* The unittest/Evaluate directory has unitests for flang-rt and Flang. A
new `CMakeLists.txt` was introduced for the flang-rt tests.
* Change the `#include` paths relative to the include directive
* clang-format on the `#include` directives
* Since the paths are part if the copyright header and include guards, a
script was used to canonicalize those
* `test/Runtime` and runtime tests in `test/Driver` are moved, but the
lit.cfg.py mechanism to execute the will only be added in #110217.
