Update on "[CIR][IR] Refactor for loops"

This patch completes the deprecation of the generic `cir.loop` operation
by adding a new `cir.for` operation and removing the `cir.loop` op. The
new representation removes some bloat and places the regions in order of
execution.

[ghstack-poisoned]

clang/include/clang/CIR/Dialect/IR/CIRDialect.h

@@ -32,8 +32,8 @@
 #include "clang/CIR/Dialect/IR/CIRTypes.h"
 
 #include "clang/CIR/Interfaces/ASTAttrInterfaces.h"
-#include "clang/CIR/Interfaces/CIROpInterfaces.h"
 #include "clang/CIR/Interfaces/CIRLoopOpInterface.h"
+#include "clang/CIR/Interfaces/CIROpInterfaces.h"
 
 namespace mlir {
 namespace OpTrait {