Merge 2025-06 LWG Motion 2

P2988R12 std::optional<T&>

Author: tkoeppe

source/support.tex

@@ -683,7 +683,7 @@
 #define @\defnlibxname{cpp_lib_freestanding_memory}@               202502L // freestanding, also in \libheader{memory}
 #define @\defnlibxname{cpp_lib_freestanding_numeric}@              202502L // freestanding, also in \libheader{numeric}
 #define @\defnlibxname{cpp_lib_freestanding_operator_new}@         @\seebelow@ // freestanding, also in \libheader{new}
-#define @\defnlibxname{cpp_lib_freestanding_optional}@             202311L // freestanding, also in \libheader{optional}
+#define @\defnlibxname{cpp_lib_freestanding_optional}@             202506L // freestanding, also in \libheader{optional}
 #define @\defnlibxname{cpp_lib_freestanding_random}@               202502L // freestanding, also in \libheader{random}
 #define @\defnlibxname{cpp_lib_freestanding_ranges}@               202306L // freestanding, also in \libheader{ranges}
 #define @\defnlibxname{cpp_lib_freestanding_ratio}@                202306L // freestanding, also in \libheader{ratio}
@@ -753,7 +753,7 @@
   // \libheader{string}, \libheader{unordered_map}, \libheader{unordered_set}, \libheader{vector}
 #define @\defnlibxname{cpp_lib_not_fn}@                            202306L // freestanding, also in \libheader{functional}
 #define @\defnlibxname{cpp_lib_null_iterators}@                    201304L // freestanding, also in \libheader{iterator}
-#define @\defnlibxname{cpp_lib_optional}@                          202110L // also in \libheader{optional}
+#define @\defnlibxname{cpp_lib_optional}@                          202506L // also in \libheader{optional}
 #define @\defnlibxname{cpp_lib_optional_range_support}@            202406L // freestanding, also in \libheader{optional}
 #define @\defnlibxname{cpp_lib_out_ptr}@                           202311L // freestanding, also in \libheader{memory}
 #define @\defnlibxname{cpp_lib_parallel_algorithm}@                201603L // also in \libheader{algorithm}, \libheader{numeric}