build: Update to c++20, c18, and meson >= 0.57.0

Change-Id: I6b4862f1aa2f8778d63b2b905762437071afd9c6
Signed-off-by: Willy Tu <wltu@google.com>
diff --git a/meson.build b/meson.build
index f84a2d3..b23a085 100644
--- a/meson.build
+++ b/meson.build
@@ -16,11 +16,11 @@
   'google-misc',
   'c',
   version: '0.1',
-  meson_version: '>=0.53.2',
+  meson_version: '>=0.57.0',
   default_options: [
     'warning_level=3',
     'werror=true',
-    'cpp_std=c++17',
+    'cpp_std=c++20',
     'c_std=c18',
     'tests=' + (meson.is_subproject() ? 'disabled' : 'auto'),
   ])
diff --git a/subprojects/acpi-power-state-daemon/meson.build b/subprojects/acpi-power-state-daemon/meson.build
index 691ae3f..c6b8f72 100644
--- a/subprojects/acpi-power-state-daemon/meson.build
+++ b/subprojects/acpi-power-state-daemon/meson.build
@@ -19,7 +19,7 @@
   default_options: [
     'warning_level=3',
     'werror=true',
-    'cpp_std=c++17',
+    'cpp_std=c++20',
   ],
 )
 
diff --git a/subprojects/metrics-ipmi-blobs/meson.build b/subprojects/metrics-ipmi-blobs/meson.build
index 0862cef..146ec72 100644
--- a/subprojects/metrics-ipmi-blobs/meson.build
+++ b/subprojects/metrics-ipmi-blobs/meson.build
@@ -19,7 +19,7 @@
   default_options: [
     'warning_level=3',
     'werror=true',
-    'cpp_std=c++17',
+    'cpp_std=c++20',
     'tests=' + (meson.is_subproject() ? 'disabled' : 'auto'),
   ],
 )
diff --git a/subprojects/ncsid/meson.build b/subprojects/ncsid/meson.build
index f53d88f..af6037a 100644
--- a/subprojects/ncsid/meson.build
+++ b/subprojects/ncsid/meson.build
@@ -16,12 +16,12 @@
   'gbmc-ncsid',
   ['cpp', 'c'],
   version: '0.1',
-  meson_version: '>=0.53.2',
+  meson_version: '>=0.57.0',
   default_options: [
     'warning_level=3',
     'werror=true',
-    'cpp_std=c++17',
-    'c_std=c11',
+    'cpp_std=c++20',
+    'c_std=c18',
     'tests=' + (meson.is_subproject() ? 'disabled' : 'auto'),
   ])
 
diff --git a/subprojects/nemora-postd/meson.build b/subprojects/nemora-postd/meson.build
index f949663..487b7c0 100644
--- a/subprojects/nemora-postd/meson.build
+++ b/subprojects/nemora-postd/meson.build
@@ -19,7 +19,7 @@
   default_options: [
     'warning_level=3',
     'werror=true',
-    'cpp_std=c++17'
+    'cpp_std=c++20'
   ],
 )