Add clang-format config file for formatting C++ code

As a consequence, drop old uncrustify config file.

.clang-format

@@ -0,0 +1,23 @@
+# NB: whenever the present file is modified, the same modification should be
+# applied to the copy in preprocessor.git
+
+# For the list of options (clang-format 14, present in Debian “bookworm” 12), see:
+#  https://releases.llvm.org/14.0.0/tools/clang/docs/ClangFormatStyleOptions.html
+# Effective configuration can be obtained with:
+#  clang-format --dump-config
+Language: Cpp
+Standard: c++20
+ColumnLimit: 100
+BasedOnStyle: GNU
+AllowShortFunctionsOnASingleLine: InlineOnly
+AlwaysBreakTemplateDeclarations: Yes
+BreakConstructorInitializers: AfterColon
+BreakInheritanceList: AfterColon
+Cpp11BracedListStyle: true
+DeriveLineEnding: false
+IndentPPDirectives: AfterHash
+PPIndentWidth: 1
+PointerAlignment: Left
+SpaceAfterTemplateKeyword: false
+SpaceBeforeParens: ControlStatements
+SpaceBeforeCpp11BracedList: true

meson.build

@@ -9,6 +9,7 @@
 project('dynare',
         'cpp', 'fortran', 'c',
         version : '6-unstable',
+        # NB: update C++ standard in .clang-format whenever the following is modified
         default_options : [ 'cpp_std=gnu++20', 'fortran_std=f2018',
                             'c_std=gnu17', 'warning_level=2' ],
         meson_version : '>=0.64.0')

preprocessor

@@ -1 +1 @@
-Subproject commit 46aa6610ab13f449ba4423e02e5df3a2cb6f7e01
+Subproject commit c4c14963a1d66009fcf04fbc63fdffff4384d9fd