all-patches/dtc: fix host-dtc build with GCC 16; cover in gcc-compat CI

.github/workflows/gcc-compat.yml

@@ -27,6 +27,7 @@ jobs:
           - 13
           - 14
           - 15
+          - 16
 
     steps:
       - name: Install build dependencies

general/package/all-patches/cmake/0002-bootstrap-guard-ghs-multi-include-gcc16.patch

@@ -0,0 +1,42 @@
+From: OpenIPC <dev@openipc.org>
+Subject: [PATCH] Source/cmake.cxx: gate cmGlobalGhsMultiGenerator include behind CMAKE_BOOTSTRAP
+
+The single reference to cmGlobalGhsMultiGenerator in cmake.cxx (line 3014,
+'this->Generators.push_back(cmGlobalGhsMultiGenerator::NewFactory());')
+is already wrapped in '#if !defined(CMAKE_BOOTSTRAP)', so the GHS generator
+is intentionally excluded from the bootstrap cmake build.
+
+The matching '#include "cmGlobalGhsMultiGenerator.h"' on line 132, however,
+is only gated by host OS, not by CMAKE_BOOTSTRAP. GCC <= 15 + glibc didn't
+care because the inline 'NewFactory()' was never ODR-used, so the
+'cmGlobalGeneratorSimpleFactory<cmGlobalGhsMultiGenerator>' template
+specialization never got emitted. Under GCC 16 the template specialization
+is emitted anyway (more aggressive vague-linkage emission / speculative
+devirtualization), and host-cmake's bootstrap link fails:
+
+  cmake.cxx:(.text+0xbfee): undefined reference to
+    'cmGlobalGhsMultiGenerator::cmGlobalGhsMultiGenerator(cmake*)'
+  cmake.cxx:(.text+0xce91): undefined reference to
+    'cmGlobalGhsMultiGenerator::GetDocumentation()'
+
+because cmGlobalGhsMultiGenerator.cxx is (correctly) not in the bootstrap
+source list.
+
+Wrap the include in the same CMAKE_BOOTSTRAP guard as the use site — same
+pattern as the existing cmGlobalXCodeGenerator block just below. The
+non-bootstrap host-cmake build is unaffected.
+
+--- a/Source/cmake.cxx
++++ b/Source/cmake.cxx
+@@ -128,9 +128,11 @@
+
+ // NOTE: the __linux__ macro is predefined on Android host too, but
+ // main CMakeLists.txt filters out this generator by host name.
++#if !defined(CMAKE_BOOTSTRAP)
+ #if (defined(__linux__) && !defined(__ANDROID__)) || defined(_WIN32)
+ #  include "cmGlobalGhsMultiGenerator.h"
+ #endif
++#endif
+
+ #if defined(__APPLE__)
+ #  if !defined(CMAKE_BOOTSTRAP)

general/package/all-patches/dtc/0001-fix-const-discarding-gcc16.patch

@@ -0,0 +1,48 @@
+From: OpenIPC <dev@openipc.org>
+Subject: [PATCH] Fix const-discarding-qualifier errors with GCC 16
+
+Starting with GCC 15 and especially GCC 16 + recent glibc, the _Generic
+wrappers for memchr() / strchr() / strrchr() return a const-qualified
+pointer when the input argument is const-qualified. With dtc's default
+-Werror, this turns previously-silent assignments into hard build errors:
+
+  libfdt/fdt_overlay.c:446: assignment discards 'const' qualifier from
+    pointer target type [-Werror=discarded-qualifiers]
+  fdtput.c:235: assignment discards 'const' qualifier from pointer target
+    type [-Werror=discarded-qualifiers]
+
+In fdt_overlay.c the local 'sep' is only read through (used for pointer
+arithmetic and dereferences for the ':' check, never to write), so it can
+be retyped to const char* without functional change. 'endptr' is split
+out as its own declaration so strtoul() still has a non-const char**
+output parameter.
+
+In fdtput.c::create_node() the function actually writes through the
+returned pointer ('*p = \'\\0\';'), which means the const on the
+'node_name' parameter has always been a lie about effects on the caller.
+The function is called with argv elements (plain char*) only, so drop
+the const from the parameter to match the actual semantics.
+
+--- a/libfdt/fdt_overlay.c
++++ b/libfdt/fdt_overlay.c
+@@ -432,7 +432,8 @@ static int overlay_fixup_phandle(void *fdt, void *fdto, int symbols_off,
+ 		const char *fixup_str = value;
+ 		uint32_t path_len, name_len;
+ 		uint32_t fixup_len;
+-		char *sep, *endptr;
++		const char *sep;
++		char *endptr;
+ 		int poffset, ret;
+
+ 		fixup_end = memchr(value, '\0', len);
+--- a/fdtput.c
++++ b/fdtput.c
+@@ -227,7 +227,7 @@ static int store_key_value(char **blob, const char *node_name,
+  * @param node_name	Name of node to create
+  * @return new node offset if found, or -1 on failure
+  */
+-static int create_node(char **blob, const char *node_name)
++static int create_node(char **blob, char *node_name)
+ {
+ 	int node = 0;
+ 	char *p;