build: pin -std=c11 for instrument-hooks core.c

The Zig-generated dist/core.c is rejected under C23 (GCC 15's default),
so pin C11 in both the Bazel and CMake builds.

Author: not-matthias

core/BUILD

@@ -49,6 +49,7 @@ instrument_hooks_cflags = [
 ]
 
 instrument_hooks_cflags_windows = [
+    "/std:c11",
     "/wd4101",  # unreferenced local variable (equivalent to -Wno-unused-variable)
     "/wd4189",  # local variable is initialized but not referenced (equivalent to -Wno-unused-but-set-variable)
     "/wd4100",  # unreferenced formal parameter (equivalent to -Wno-unused-parameter)
@@ -66,8 +67,8 @@ cc_library(
     copts = select({
         ":windows_strict_warnings": ["/W4","/WX"] + instrument_hooks_cflags_windows,
         ":windows": instrument_hooks_cflags_windows,
-        ":strict_warnings_enabled": ["-Wall", "-Werror"] + instrument_hooks_cflags,
-        "//conditions:default": instrument_hooks_cflags,
+        ":strict_warnings_enabled": ["-std=c11", "-Wall", "-Werror"] + instrument_hooks_cflags,
+        "//conditions:default": ["-std=c11"] + instrument_hooks_cflags,
     }),
     visibility = ["//visibility:public"],
 )

core/CMakeLists.txt

@@ -27,6 +27,13 @@ set(instrument_hooks_SOURCE_DIR ${instrument_hooks_repo_SOURCE_DIR})
 # Add the instrument_hooks library
 add_library(instrument_hooks STATIC ${instrument_hooks_SOURCE_DIR}/dist/core.c)
 
+# Pin C11: the Zig-generated core.c is rejected under C23 (e.g. GCC 15's default),
+# which mangles [[noreturn]] placement in the embedded zig.h.
+set_target_properties(
+    instrument_hooks
+    PROPERTIES C_STANDARD 11 C_STANDARD_REQUIRED ON
+)
+
 target_include_directories(
     instrument_hooks
     PUBLIC