Added mauke's test

Author: bingos

dist/ExtUtils-CBuilder/t/03-cplusplus.t

@@ -26,7 +26,18 @@ else {
   plan tests => 7;
 }
 
-ok $b, "created EU::CB object";
+{
+    # GH #23146
+    my $fake_cc = File::Spec->rel2abs(File::Spec->catfile(qw(some directory what doesnt exist), 'cc'));
+    my $b = ExtUtils::CBuilder->new(
+        quiet => $quiet,
+        config => {
+            cc => $fake_cc,
+        },
+    );
+
+    is $b->{config}{cxx}, $fake_cc, "did not search PATH for C++ compiler when given absolute path to C compiler";
+}
 
 ok $b->have_cplusplus, "have_cplusplus";