headers: Define IMAGE_RUNTIME_FUNCTION_ENTRY for aarch64

We've had a definition of IMAGE_ARM64_RUNTIME_FUNCTION_ENTRY since
0f9569488ba7e48472183765a7ae6555ed990f4a in 2018, but we missed
the definition of the generic IMAGE_RUNTIME_FUNCTION_ENTRY to
point to the arch specific version of it.

The shorter names RUNTIME_FUNCTION and PRUNTIME_FUNCTION already
are typedefs for IMAGE_ARM64_RUNTIME_FUNCTION_ENTRY though.

Signed-off-by: Martin Storsjö <martin@martin.st>

mingw-w64-headers/include/winnt.h

diff --git a/mingw-w64-headers/include/winnt.h b/mingw-w64-headers/include/winnt.h
index 6120c92..e76e302 100644
--- a/mingw-w64-headers/include/winnt.h
+++ b/mingw-w64-headers/include/winnt.h
@@ -8537,6 +8537,9 @@
 #elif defined (__arm__)
     typedef IMAGE_ARM_RUNTIME_FUNCTION_ENTRY IMAGE_RUNTIME_FUNCTION_ENTRY;
     typedef PIMAGE_ARM_RUNTIME_FUNCTION_ENTRY PIMAGE_RUNTIME_FUNCTION_ENTRY;
+#elif defined (__aarch64__)
+    typedef IMAGE_ARM64_RUNTIME_FUNCTION_ENTRY IMAGE_RUNTIME_FUNCTION_ENTRY;
+    typedef PIMAGE_ARM64_RUNTIME_FUNCTION_ENTRY PIMAGE_RUNTIME_FUNCTION_ENTRY;
 #else
     typedef _IMAGE_RUNTIME_FUNCTION_ENTRY IMAGE_RUNTIME_FUNCTION_ENTRY;
     typedef _PIMAGE_RUNTIME_FUNCTION_ENTRY PIMAGE_RUNTIME_FUNCTION_ENTRY;