[flang] NoArgv.FdateNotSupported unit test fails on macOS

[luporl]

[ RUN      ] NoArgv.FdateNotSupported
/path/to/llvm-project/flang/unittests/Runtime/CommandTest.cpp:285: Failure
Death test: fdate_(input, sizeof(input))
    Result: failed to die.
 Error msg:
[  DEATH   ]

[  FAILED  ] NoArgv.FdateNotSupported (1 ms)

Steps to reproduce:
ninja check-flang
or
./tools/flang/unittests/Runtime/FlangRuntimeTests --gtest_filter=NoArgv.FdateNotSupported

[llvmbot]

@llvm/issue-subscribers-flang-runtime

Author: Leandro Lupori (luporl)

``` [ RUN ] NoArgv.FdateNotSupported /path/to/llvm-project/flang/unittests/Runtime/CommandTest.cpp:285: Failure Death test: fdate_(input, sizeof(input)) Result: failed to die. Error msg: [ DEATH ]

[ FAILED ] NoArgv.FdateNotSupported (1 ms)

Steps to reproduce:
`ninja check-flang`
or
`./tools/flang/unittests/Runtime/FlangRuntimeTests --gtest_filter=NoArgv.FdateNotSupported`
</details>

[luporl]

Fixed by #84478.

[llvmbot]

@llvm/issue-subscribers-flang-frontend

Author: Leandro Lupori (luporl)

``` [ RUN ] NoArgv.FdateNotSupported /path/to/llvm-project/flang/unittests/Runtime/CommandTest.cpp:285: Failure Death test: fdate_(input, sizeof(input)) Result: failed to die. Error msg: [ DEATH ]

[ FAILED ] NoArgv.FdateNotSupported (1 ms)

Steps to reproduce:
`ninja check-flang`
or
`./tools/flang/unittests/Runtime/FlangRuntimeTests --gtest_filter=NoArgv.FdateNotSupported`
</details>

[luporl]

NoArgv.FdateNotSupported unit test is failing again on macOS, with the same error, since the flang runtime was moved to flang-rt.