Adds deprecation messages for MIPS cross-builds

CHANGELOG.md

Index: CHANGELOG.md
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2728e6aea9cc8772e74843b91f4386fac300dad1..8031041231dbc39b2cbccba7a22ac517a555df62 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -46,7 +46,6 @@ entirely to allow inference to fill in the type.
       1.24, violations are only reported (on stdout or stderr), but a future
       version of the Dart SDK will change this to throwing a `StateError`.
 
-
 ### Dart VM
 
 ### Tool Changes
@@ -61,6 +60,12 @@ entirely to allow inference to fill in the type.
     * Add self-test validation to ensure formatter bugs do not cause user code
       to be lost.
 
+### Infrastructure changes
+
+* As of this release, we'll show a warning when using the MIPS architecture.
+  Unless we learn about any critical use of Dart on MIPS in the meantime, we're
+  planning to deprecate support for MIPS starting with the next stable release.
+
 ## 1.23.0
 
 #### Strong Mode