[diff.cpp20.{dcl,expr}] Fix subclause order to match main document

Author: tkoeppe

source/compatibility.tex

@@ -39,36 +39,6 @@
 auto c = L"a" U"b";             // was conditionally-supported; now ill-formed
 \end{codeblock}
 
-\rSec2[diff.cpp20.dcl]{\ref{dcl.dcl}: declarations}
-
-\diffref{dcl.init.string}
-\change
-UTF-8 string literals may initialize arrays of \keyword{char} or
-\tcode{\keyword{unsigned} \keyword{char}}.
-\rationale
-Compatibility with previously written code that conformed to previous versions of this document.
-\effect
-Arrays of \keyword{char} or \tcode{\keyword{unsigned} \keyword{char}}
-may now be initialized with a UTF-8 string literal.
-This can affect initialization that includes arrays
-that are directly initialized within class types, typically aggregates.
-For example:
-\begin{codeblock}
-struct A {
-  char8_t s[10];
-};
-struct B {
-  char s[10];
-};
-
-void f(A);
-void f(B);
-
-int main() {
-  f({u8""});            // ambiguous
-}
-\end{codeblock}
-
 \rSec2[diff.cpp20.expr]{\ref{expr}: expressions}
 
 \diffref{expr.prim.id.unqual}
@@ -99,6 +69,36 @@
                         // now equivalent to \tcode{arr.operator[](1, 2)} or ill-formed
 \end{codeblock}
 
+\rSec2[diff.cpp20.dcl]{\ref{dcl.dcl}: declarations}
+
+\diffref{dcl.init.string}
+\change
+UTF-8 string literals may initialize arrays of \keyword{char} or
+\tcode{\keyword{unsigned} \keyword{char}}.
+\rationale
+Compatibility with previously written code that conformed to previous versions of this document.
+\effect
+Arrays of \keyword{char} or \tcode{\keyword{unsigned} \keyword{char}}
+may now be initialized with a UTF-8 string literal.
+This can affect initialization that includes arrays
+that are directly initialized within class types, typically aggregates.
+For example:
+\begin{codeblock}
+struct A {
+  char8_t s[10];
+};
+struct B {
+  char s[10];
+};
+
+void f(A);
+void f(B);
+
+int main() {
+  f({u8""});            // ambiguous
+}
+\end{codeblock}
+
 \rSec2[diff.cpp20.temp]{\ref{temp}: templates}
 
 \diffref{temp.deduct.type}