d: Add C++23 to CppStdRevision enum

D front-end changes:

	- The compiler now accepts `-fextern-std=c++23'

gcc/d/ChangeLog:

	* dmd/MERGE: Merge upstream dmd 94950cae58.
	* d-lang.cc (d_handle_option): Add case for CppStdRevisionCpp23.
	* gdc.texi: Document -fextern-std=c++23.
	* lang.opt (fextern-std=): Add c++23.

libphobos/ChangeLog:

	* libdruntime/MERGE: Merge upstream druntime 94950cae58.

Reviewed-on: https://github.com/dlang/dmd/pull/21043

8 files changed, 12 insertions, 3 deletions

diff --git a/gcc/d/d-lang.cc b/gcc/d/d-lang.cc
index 21f46ff..b3786be 100644
--- a/gcc/d/d-lang.cc
+++ b/gcc/d/d-lang.cc
@@ -510,6 +510,7 @@ d_handle_option (size_t scode, const char *arg, HOST_WIDE_INT value,
 	case CppStdRevisionCpp14:
 	case CppStdRevisionCpp17:
 	case CppStdRevisionCpp20:
+	case CppStdRevisionCpp23:
 	  global.params.cplusplus = (CppStdRevision) value;
 	  break;
 
diff --git a/gcc/d/dmd/MERGE b/gcc/d/dmd/MERGE
index f274580..9982d0d 100644
--- a/gcc/d/dmd/MERGE
+++ b/gcc/d/dmd/MERGE
@@ -1,4 +1,4 @@
-8db14cf8467ca25256904d51169b176c9c89afb1
+94950cae582d89f5ba2720786522f669f620f9d1
 
 The first line of this file holds the git revision number of the last
 merge done from the dlang/dmd repository.
diff --git a/gcc/d/dmd/globals.d b/gcc/d/dmd/globals.d
index 4a637b5..900c554 100644
--- a/gcc/d/dmd/globals.d
+++ b/gcc/d/dmd/globals.d
@@ -62,6 +62,7 @@ enum CppStdRevision : uint
     cpp14 = 2014_02,
     cpp17 = 2017_03,
     cpp20 = 2020_02,
+    cpp23 = 2023_02,
 }
 
 /// Trivalent boolean to represent the state of a `revert`able change
diff --git a/gcc/d/dmd/globals.h b/gcc/d/dmd/globals.h
index cdb0663..69fe709 100644
--- a/gcc/d/dmd/globals.h
+++ b/gcc/d/dmd/globals.h
@@ -73,7 +73,8 @@ enum CppStdRevision
     CppStdRevisionCpp11 = 201103,
     CppStdRevisionCpp14 = 201402,
     CppStdRevisionCpp17 = 201703,
-    CppStdRevisionCpp20 = 202002
+    CppStdRevisionCpp20 = 202002,
+    CppStdRevisionCpp23 = 202302,
 };
 
 /// Trivalent boolean to represent the state of a `revert`able change
diff --git a/gcc/d/gdc.texi b/gcc/d/gdc.texi
index 1a84d6d..2cb0c4a62 100644
--- a/gcc/d/gdc.texi
+++ b/gcc/d/gdc.texi
@@ -273,6 +273,8 @@ Sets @code{__traits(getTargetInfo, "cppStd")} to @code{201703}.
 This is the default.
 @item c++20
 Sets @code{__traits(getTargetInfo, "cppStd")} to @code{202002}.
+@item c++23
+Sets @code{__traits(getTargetInfo, "cppStd")} to @code{202302}.
 @end table
 
 @opindex finvariants
diff --git a/gcc/d/lang.opt b/gcc/d/lang.opt
index f769a71..50c6f2f 100644
--- a/gcc/d/lang.opt
+++ b/gcc/d/lang.opt
@@ -320,6 +320,9 @@ Enum(extern_stdcpp) String(c++17) Value(201703)
 EnumValue
 Enum(extern_stdcpp) String(c++20) Value(202002)
 
+EnumValue
+Enum(extern_stdcpp) String(c++23) Value(202302)
+
 fignore-unknown-pragmas
 D
 Ignore unsupported pragmas.
diff --git a/libphobos/libdruntime/MERGE b/libphobos/libdruntime/MERGE
index 18c9d11..9982d0d 100644
--- a/libphobos/libdruntime/MERGE
+++ b/libphobos/libdruntime/MERGE
@@ -1,4 +1,4 @@
-d2ee11364c25ca8865eb0acb9596a6147532ef41
+94950cae582d89f5ba2720786522f669f620f9d1
 
 The first line of this file holds the git revision number of the last
 merge done from the dlang/dmd repository.
diff --git a/libphobos/libdruntime/core/stdcpp/xutility.d b/libphobos/libdruntime/core/stdcpp/xutility.d
index 5e2e711..f93df68 100644
--- a/libphobos/libdruntime/core/stdcpp/xutility.d
+++ b/libphobos/libdruntime/core/stdcpp/xutility.d
@@ -35,6 +35,7 @@ enum CppStdRevision : uint
     cpp14 = 201402,
     cpp17 = 201703,
     cpp20 = 202002,
+    cpp23 = 202302,
 }
 
 /**