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

fusl/arch/powerpc/bits/fenv.h

+#define FE_TONEAREST    0
+#define FE_TOWARDZERO   1
+#define FE_UPWARD       2
+#define FE_DOWNWARD     3
+
+#define FE_INEXACT      0x02000000
+#define FE_DIVBYZERO    0x04000000
+#define FE_UNDERFLOW    0x08000000
+#define FE_OVERFLOW     0x10000000
+#define FE_INVALID      0x20000000
+
+#define FE_ALL_EXCEPT   0x3e000000
+
+#ifdef _GNU_SOURCE
+#define FE_INVALID_SNAN         0x01000000
+#define FE_INVALID_ISI          0x00800000
+#define FE_INVALID_IDI          0x00400000
+#define FE_INVALID_ZDZ          0x00200000
+#define FE_INVALID_IMZ          0x00100000
+#define FE_INVALID_COMPARE      0x00080000
+#define FE_INVALID_SOFTWARE     0x00000400
+#define FE_INVALID_SQRT         0x00000200
+#define FE_INVALID_INTEGER_CONVERSION   0x00000100
+
+#define FE_ALL_INVALID          0x01f80700
+#endif
+
+typedef unsigned fexcept_t;
+typedef double fenv_t;
+
+#define FE_DFL_ENV ((const fenv_t *)-1)