Add xrefdelta entries for consolidated subclauses.

Author: zygoloid

source/xrefdelta.tex

@@ -168,6 +168,19 @@
 \movedxref{diff.cpp17.dcl.decl}{diff.cpp17.dcl.dcl}
 \movedxref{diff.cpp17.special}{diff.cpp17.class}
 
+% P1148R0 consolidated some Clause 20 subclauses.
+\movedxref{string.rfind}{string.find}
+\movedxref{string.find.first.of}{string.find}
+\movedxref{string.find.last.of}{string.find}
+\movedxref{string.find.first.not.of}{string.find}
+\movedxref{string.find.last.not.of}{string.find}
+\movedxref{string.operator==}{string.comparison}
+\movedxref{string.op!=}{string.comparison}
+\movedxref{string.op<}{string.comparison}
+\movedxref{string.op>}{string.comparison}
+\movedxref{string.op<=}{string.comparison}
+\movedxref{string.op>=}{string.comparison}
+
 % Deprecated features.
 %\deprxref{old.label}  (if moved to depr.old.label, otherwise use \movedxref)