[flang][driver] Forward `-fopenmp` to the host compiler

[awarzynski]

Summary

This patch only modifies flang - the bash wrapper script.

-fopenmp is required to enable the OpenMP extension in the frontend
and to make sure that the required libraries are linked when generating
the final binary. This patch makes sure that -fopnemp is used for both
unparsing and the code generation (via the host compiler).

[jdoerfert]

LG

[clementval]

I think you can move -fopenacc as well.

[awarzynski]

Include -fopenacc in this change

[awarzynski]

In D106871#2907327, @clementval wrote:

I think you can move -fopenacc as well.

Sure thing! I don't have an OpenACC example to test this with, but it's a fairly straightforward change. If there are no further comments, I will merge this tomorrow.

flang/tools/f18/flang.in

if
       [[ $opt == "-ffixed-form" ]] ||
       [[ $opt =~ ^-ffixed-line-length=.* ]] ||
       [[ $opt == "-ffree-form" ]] ||
       [[ $opt == "-fimplicit-none" ]] ||
       [[ $opt =~ ^-finput-charset=.* ]] ||
       [[ $opt == "-flarge-sizes" ]] ||
       [[ $opt == "-flogical-abbreviations" ]] ||
       [[ $opt == "-fno-color-diagnostics" ]] ||
-      [[ $opt == "-fopenacc" ]] ||
-      [[ $opt == "-fopenmp" ]] ||
       [[ $opt == "-fxor-operator" ]] ||
       [[ $opt == "-help" ]] ||
       [[ $opt == "-nocpp" ]] ||
       [[ $opt == "-pedantic" ]] ||
       [[ $opt =~ ^-std=.* ]] ||
       [[ $opt =~ ^-U.* ]] ||
       [[ $opt == "-Werror" ]]; then
       flang_opts+=($opt)
     elif
       # These options are not supported by `flang-new`. There is also no point
       # in forwarding them to the host compiler as the output from
       # `-fdebug-unparse` will always be in free form.
       [[ $opt == "-Mfixed" ]] || [[ $opt == "-Mfree" ]]; then
       :
-    elif [[ $opt =~ -I.* ]] || [[ $opt =~ -J.* ]]; then
+    elif
       # Options that are needed for both Flang and the external driver.
+      [[ $opt =~ -I.* ]] ||
+      [[ $opt =~ -J.* ]] ||
+      [[ $opt == "-fopenmp" ]] ||
+      [[ $opt == "-fopenacc" ]] ||
+      ; then
       flang_opts+=($opt)
       fc_opts+=($opt)
     else
       # All other options are claimed for the external driver.
       fc_opts+=($opt)
     fi
   done
 }