[dotnet] add $!type and $!result parameters to DNST::If, so the resul…

…t temporary can optionally be ignored/left out,

and if not, the type can be set (other than the default RakudoObject.

dotnet/compiler/DNST.pm

@@ -262,17 +262,31 @@ class DNST::Throw is DNST::Node {
 }
 
 class DNST::If is DNST::Node {
+    has $!type;
     has $!bool;
+    has $!result;
 
     method bool($set?) {
         if $set { $!bool := $set }
         $!bool
     }
 
-    method new(:$bool, *@children) {
+    method type($set?) {
+        if $set { $!type := $set }
+        $!type
+    }
+
+    method result($set?) {
+        if $set { $!result := $set }
+        $!result
+    }
+
+    method new(:$bool, :$type, :$result, *@children) {
         my $obj := self.CREATE;
         $obj.set_children(@children);
         $obj.bool($bool);
+        $obj.type(pir::defined($type) ?? $type !! 'RakudoObject');
+        $obj.result(pir::defined($result) ?? $result !! 1);
         $obj;
     }
 }

dotnet/compiler/DNST2CSharp.pm

@@ -191,28 +191,29 @@ our multi sub cs_for(DNST::If $if) {
     unless +@($if) >= 2 { pir::die('A DNST::If node must have at least 2 children') }
 
     # Need a variable to put the final result in.
-    my $if_result := get_unique_id('if_result');
+    my $if_result := get_unique_id('if_result') if $if.result;
 
     # Get the conditional and emit if.
     my $code := cs_for((@($if))[0]);
     $code := $code ~
-             "        RakudoObject $if_result = null;\n" ~
+             "        " ~ $if.type ~ " $if_result = null;\n" if $if.result;
+    $code := $code ~
              "        if ($*LAST_TEMP" ~ ($if.bool ?? "" !! " != 0") ~ ") \{\n";
 
     # Compile branch(es).
     $*LAST_TEMP := 'null';
     $code := $code ~ cs_for((@($if))[1]);
-    $code := $code ~ "        $if_result = $*LAST_TEMP;\n" ~
-                     "        }\n";
+    $code := $code ~ "        $if_result = $*LAST_TEMP;\n" if $if.result;
+    $code := $code ~ "        }\n";
     if +@($if) == 3 {
         $*LAST_TEMP := 'null';
         $code := $code ~ "        else \{\n";
         $code := $code ~ cs_for((@($if))[2]);
-        $code := $code ~ "        $if_result = $*LAST_TEMP;\n" ~
-                         "        }\n";
+        $code := $code ~ "        $if_result = $*LAST_TEMP;\n" if $if.result;
+        $code := $code ~ "        }\n";
     }
 
-    $*LAST_TEMP := $if_result;
+    $*LAST_TEMP := $if_result if $if.result;
     return $code;
 }