Add a "fork" of musl as //fusl.

fusl/arch/x86_64/bits/stdint.h

Index: fusl/arch/x86_64/bits/stdint.h
diff --git a/fusl/arch/x86_64/bits/stdint.h b/fusl/arch/x86_64/bits/stdint.h
new file mode 100644
index 0000000000000000000000000000000000000000..1bb147f24e02b0445b78079291aadea6c5c4a05e
--- /dev/null
+++ b/fusl/arch/x86_64/bits/stdint.h
@@ -0,0 +1,20 @@
+typedef int32_t int_fast16_t;
+typedef int32_t int_fast32_t;
+typedef uint32_t uint_fast16_t;
+typedef uint32_t uint_fast32_t;
+
+#define INT_FAST16_MIN  INT32_MIN
+#define INT_FAST32_MIN  INT32_MIN
+
+#define INT_FAST16_MAX  INT32_MAX
+#define INT_FAST32_MAX  INT32_MAX
+
+#define UINT_FAST16_MAX UINT32_MAX
+#define UINT_FAST32_MAX UINT32_MAX
+
+#define INTPTR_MIN      INT64_MIN
+#define INTPTR_MAX      INT64_MAX
+#define UINTPTR_MAX     UINT64_MAX
+#define PTRDIFF_MIN     INT64_MIN
+#define PTRDIFF_MAX     INT64_MAX
+#define SIZE_MAX        UINT64_MAX