vbscript: Support using function return value in expressions.

dlls/vbscript/interp.c

@@ -104,8 +104,7 @@ static HRESULT lookup_identifier(exec_ctx_t *ctx, BSTR name, vbdisp_invoke_type_
     DISPID id;
     HRESULT hres;
 
-    if(invoke_type == VBDISP_LET
-            && (ctx->func->type == FUNC_FUNCTION || ctx->func->type == FUNC_PROPGET || ctx->func->type == FUNC_DEFGET)
+    if((ctx->func->type == FUNC_FUNCTION || ctx->func->type == FUNC_PROPGET || ctx->func->type == FUNC_DEFGET)
        && !wcsicmp(name, ctx->func->name)) {
         ref->type = REF_VAR;
         ref->u.v = &ctx->ret_val;

dlls/vbscript/tests/lang.vbs

@@ -1621,4 +1621,13 @@ with new TestPropSyntax
      ok .prop = 1, ".prop = "&.prop
 end with
 
+function testsetresult(x, y)
+    set testsetresult = new TestPropSyntax
+    testsetresult.prop = x
+    y = testsetresult.prop + 1
+end function
+
+set x = testsetresult(1, 2)
+ok x.prop = 1, "x.prop = " & x.prop
+
 reportSuccess()