[gcc r15-3662] libstdc++: Add .editorconfig files

[Jonathan Wakely]

https://gcc.gnu.org/g:eb67e2396f3ee834bf3a8299f5b6d93ba82d3950

commit r15-3662-geb67e2396f3ee834bf3a8299f5b6d93ba82d3950
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Mon Sep 16 10:04:40 2024 +0100

    libstdc++: Add .editorconfig files
    
    These config files set default formatting behaviour for a large number
    of common editors, see https://editorconfig.org
    
    The root=true setting in libstdc++-v3/.editorconfig prevents looking in
    parent directories for additional settings. If we add a .editorconfig at
    the top-level we might want to use root=true there instead, and allow
    libstdc++-v3/.editorconfig to inherit some some settings from there (and
    only override things we want to do differently).
    
    libstdc++-v3/ChangeLog:
    
            * .editorconfig: New file.
            * include/std/.editorconfig: New file.

Diff:
---
 libstdc++-v3/.editorconfig             | 38 ++++++++++++++++++++++++++++++++++
 libstdc++-v3/include/std/.editorconfig | 10 +++++++++
 2 files changed, 48 insertions(+)

diff --git a/libstdc++-v3/.editorconfig b/libstdc++-v3/.editorconfig
new file mode 100644
index 000000000000..88107cedda21
--- /dev/null
+++ b/libstdc++-v3/.editorconfig
@@ -0,0 +1,38 @@
+# top-most EditorConfig file for libstdc++-v3
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+
+[*.h,*.cc]
+charset = utf-8
+indent_style = tab
+indent_size = 2
+tab_width = 8
+trim_trailing_whitespace = true
+
+[Makefile*,ChangeLog*]
+indent_style = tab
+indent_size = 8
+trim_trailing_whitespace = true
+
+[ChangeLog*]
+charset = utf-8
+
+[*.xml]
+charset = utf-8
+indent_size = 2
+tab_width = 8
+trim_trailing_whitespace = true
+
+[*.py]
+indent_style = space
+indent_size = 4
+trim_trailing_whitespace = true
+
+[*.exp]
+indent_style = tab
+indent_size = 4
+tab_width = 8
+trim_trailing_whitespace = true
diff --git a/libstdc++-v3/include/std/.editorconfig b/libstdc++-v3/include/std/.editorconfig
new file mode 100644
index 000000000000..97ca1923cf84
--- /dev/null
+++ b/libstdc++-v3/include/std/.editorconfig
@@ -0,0 +1,10 @@
+# Inherit settings from EditorConfig files above this dir.
+root = false
+
+# All files under this directory are C++ headers.
+[*]
+charset = utf-8
+indent_style = tab
+indent_size = 2
+tab_width = 8
+trim_trailing_whitespace = true