[LLVM] Add missing stdint include to Bit.h

To fix failing builds on Windows on Arm:
https://lab.llvm.org/staging/#/builders/59/builds/928/steps/4/logs/stdio

<...>/ADT/bit.h(50,5): error: unknown type name 'uint32_t'
    uint32_t v = Value;
    ^

llvm/include/llvm/ADT/bit.h

@@ -17,6 +17,8 @@
 #include <cstring>
 #include <type_traits>
 
+#include <stdint.h>
+
 namespace llvm {
 
 // This implementation of bit_cast is different from the C++20 one in two ways: