recipes-google: Migrate builds to C++23

Set -Dcpp_std=c++23 and add necessary LDFLAGS/CXXFLAGS for Google
daemons (shared-memory, nvmed, pldmd-openbmc-rebase, rde-support).

Tested:
Verified build with GCC 15 and C++23 across gBMC platforms.
- platform11: http://fusion2/3ff2006d-9c03-3f0c-99fd-bcefc6aaca1f
- platform11: http://fusion2/982d88b5-28f9-38ef-a3a2-d824b919c13c
- platform5: http://fusion2/a7e89bcd-86a0-33b2-8f33-2bb24ef3afb5
- platform15: http://fusion2/e56dcb19-6dcd-35a0-b5ee-30740fbf27df
- platform17: http://fusion2/d0e6af61-eb95-3a70-a6a3-d1bdab987ea2
- platform18: http://fusion2/cda6ba3a-58f5-3907-b584-04786b9fe634
- platform25: http://fusion2/714cc620-6f0a-3bfd-90dd-95356b62b54b
Google-Bug-Id: 482144905
Change-Id: I65f1385b40796506fb178957ab8d889e3139559c
Signed-off-by: Willy Tu <wltu@google.com>

recipes-google/g3-shared-libs/shared-memory_git.bb

diff --git a/recipes-google/g3-shared-libs/shared-memory_git.bb b/recipes-google/g3-shared-libs/shared-memory_git.bb
index be49995..432257f 100644
--- a/recipes-google/g3-shared-libs/shared-memory_git.bb
+++ b/recipes-google/g3-shared-libs/shared-memory_git.bb
@@ -4,9 +4,9 @@
 require g3-shared-libs.inc
 G3_PROJ="shared_memory"
 DEPENDS:append = " boost abseil-cpp"
+LDFLAGS:append = " -latomic"
 
 FILES:${PN} = " \
   ${libdir}/libshared_memory${SOLIBS} \
   ${includedir}/shared_memory/* \
 "
-

recipes-google/nvme/nvmed.bb

diff --git a/recipes-google/nvme/nvmed.bb b/recipes-google/nvme/nvmed.bb
index 9952800..3ab7ba9 100644
--- a/recipes-google/nvme/nvmed.bb
+++ b/recipes-google/nvme/nvmed.bb
@@ -30,6 +30,7 @@
 inherit pkgconfig meson systemd
 
 EXTRA_OEMESON:append = " \
+    -Dcpp_std=c++23 \
     -Dadc=disabled \
     -Dexit-air=disabled \
     -Dexternal=disabled \

recipes-google/pldmd/pldmd-openbmc-rebase_git.bb

diff --git a/recipes-google/pldmd/pldmd-openbmc-rebase_git.bb b/recipes-google/pldmd/pldmd-openbmc-rebase_git.bb
index 00842f7..694f8a5 100644
--- a/recipes-google/pldmd/pldmd-openbmc-rebase_git.bb
+++ b/recipes-google/pldmd/pldmd-openbmc-rebase_git.bb
@@ -32,8 +32,11 @@
         -Doem-ibm=disabled \
         -Doem-ampere=disabled \
         -Dsoftoff=disabled \
+        -Dcpp_std=c++23 \
         "
 
 do_install:append () {
     rm -rf ${D}/usr/share
 }
+
+CXXFLAGS += "-Wno-error=sign-compare"

recipes-google/rde-support/rde-support_git.bb

diff --git a/recipes-google/rde-support/rde-support_git.bb b/recipes-google/rde-support/rde-support_git.bb
index 1a72bf3..5b8ff0f 100644
--- a/recipes-google/rde-support/rde-support_git.bb
+++ b/recipes-google/rde-support/rde-support_git.bb
@@ -46,3 +46,4 @@
     rmdir ${D}${datadir} || true
 }
 
+CXXFLAGS:append = " -Wno-error=deprecated-declarations"