[profile] Add InstrProfilingInternal.c.o to Darwin kext builtins

Fixes a build failure in the Darwin kernel. Tested with:

% nm -m ./lib/libclang_rt.cc_kext_x86_64_osx.a | grep lprofSetProfileDumped

rdar://66249602

compiler-rt/cmake/Modules/CompilerRTDarwinUtils.cmake

@@ -398,7 +398,8 @@ macro(darwin_add_builtin_libraries)
   set(PROFILE_SOURCES ../profile/InstrProfiling 
                       ../profile/InstrProfilingBuffer
                       ../profile/InstrProfilingPlatformDarwin
-                      ../profile/InstrProfilingWriter)
+                      ../profile/InstrProfilingWriter
+                      ../profile/InstrProfilingInternal)
   foreach (os ${ARGN})
     list_intersect(DARWIN_BUILTIN_ARCHS DARWIN_${os}_BUILTIN_ARCHS BUILTIN_SUPPORTED_ARCH)
     foreach (arch ${DARWIN_BUILTIN_ARCHS})

compiler-rt/lib/profile/InstrProfiling.c

@@ -6,6 +6,9 @@
 |*
 \*===----------------------------------------------------------------------===*/
 
+// Note: This is linked into the Darwin kernel, and must remain compatible
+// with freestanding compilation. See `darwin_add_builtin_libraries`.
+
 #include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -17,7 +20,6 @@
 #define INSTR_PROF_VALUE_PROF_DATA
 #include "profile/InstrProfData.inc"
 
-
 COMPILER_RT_VISIBILITY uint64_t __llvm_profile_get_magic(void) {
   return sizeof(void *) == sizeof(uint64_t) ? (INSTR_PROF_RAW_MAGIC_64)
                                             : (INSTR_PROF_RAW_MAGIC_32);

compiler-rt/lib/profile/InstrProfilingBuffer.c

@@ -6,6 +6,9 @@
 |*
 \*===----------------------------------------------------------------------===*/
 
+// Note: This is linked into the Darwin kernel, and must remain compatible
+// with freestanding compilation. See `darwin_add_builtin_libraries`.
+
 #include "InstrProfiling.h"
 #include "InstrProfilingInternal.h"
 #include "InstrProfilingPort.h"

compiler-rt/lib/profile/InstrProfilingInternal.c

@@ -6,6 +6,9 @@
 |*
 \*===----------------------------------------------------------------------===*/
 
+// Note: This is linked into the Darwin kernel, and must remain compatible
+// with freestanding compilation. See `darwin_add_builtin_libraries`.
+
 #if !defined(__Fuchsia__)
 
 #include "InstrProfilingInternal.h"

compiler-rt/lib/profile/InstrProfilingPlatformDarwin.c

@@ -6,6 +6,9 @@
 |*
 \*===----------------------------------------------------------------------===*/
 
+// Note: This is linked into the Darwin kernel, and must remain compatible
+// with freestanding compilation. See `darwin_add_builtin_libraries`.
+
 #include "InstrProfiling.h"
 
 #if defined(__APPLE__)

compiler-rt/lib/profile/InstrProfilingWriter.c

@@ -6,6 +6,9 @@
 |*
 \*===----------------------------------------------------------------------===*/
 
+// Note: This is linked into the Darwin kernel, and must remain compatible
+// with freestanding compilation. See `darwin_add_builtin_libraries`.
+
 #ifdef _MSC_VER
 /* For _alloca */
 #include <malloc.h>