gn docs: Update toolchain example in the language reference

tools/gn/docs/language.md

Index: tools/gn/docs/language.md
diff --git a/tools/gn/docs/language.md b/tools/gn/docs/language.md
index e6e80d31493eefe859b68b72027b4762c0184fcb..514541d25918e783ee7312acc62a611ae7fde9b6 100644
--- a/tools/gn/docs/language.md
+++ b/tools/gn/docs/language.md
@@ -607,8 +607,8 @@ toolchain("32") {
   ... more tools ...
 
   # Arguments to the build when re-invoking as a secondary toolchain.
-  toolchain_args() {
-    toolchain_cpu = "x86"
+  toolchain_args = {
+    current_cpu = "x86"
   }
 }
 
@@ -619,8 +619,8 @@ toolchain("64") {
   ... more tools ...
 
   # Arguments to the build when re-invoking as a secondary toolchain.
-  toolchain_args() {
-    toolchain_cpu = "x64"
+  toolchain_args = {
+    current_cpu = "x64"
   }
 }
 ```