[flang][cuda] Using the -x cuda option switch to cc1 instead of fc1

[clementval]

When trying to compile a cuda fortran example with -x cuda, cc1 is picked but fc1 should still be used.

[llvmbot]

@llvm/issue-subscribers-flang-driver

Author: Valentin Clement (バレンタイン クレメン) (clementval)

When trying to compile a cuda fortran example with `-x cuda`, `cc1` is picked but `fc1` should still be used.

[clementval]

@banach-space Do you have any idea where this switch is made?

[banach-space]

Roughly here:

llvm-project/clang/lib/Driver/ToolChain.cpp

Lines 870 to 878 in 15e1e3b

	Tool *ToolChain::SelectTool(const JobAction &JA) const {
	if (D.IsFlangMode() && getDriver().ShouldUseFlangCompiler(JA)) return getFlang();
	if (getDriver().ShouldUseClangCompiler(JA)) return getClang();
	Action::ActionClass AC = JA.getKind();
	if (AC == Action::AssembleJobClass && useIntegratedAs() &&
	!getTriple().isOSAIX())
	return getClangAs();
	return getTool(AC);
	}

[clementval]

Thanks for the pointer @banach-space !