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

fusl/arch/i386/bits/user.h

+#undef __WORDSIZE
+#define __WORDSIZE 32
+
+typedef struct user_fpregs_struct
+{
+        long cwd, swd, twd, fip, fcs, foo, fos, st_space[20];
+} elf_fpregset_t;
+
+typedef struct user_fpxregs_struct
+{
+        unsigned short cwd, swd, twd, fop;
+        long fip, fcs, foo, fos, mxcsr, reserved;
+        long st_space[32], xmm_space[32], padding[56];
+} elf_fpxregset_t;
+
+struct user_regs_struct
+{
+        long ebx, ecx, edx, esi, edi, ebp, eax, xds, xes, xfs, xgs;
+        long orig_eax, eip, xcs, eflags, esp, xss;
+};
+
+#define ELF_NGREG 17
+typedef unsigned long elf_greg_t, elf_gregset_t[ELF_NGREG];
+
+struct user
+{
+        struct user_regs_struct         regs;
+        int                             u_fpvalid;
+        struct user_fpregs_struct       i387;
+        unsigned long                   u_tsize;
+        unsigned long                   u_dsize;
+        unsigned long                   u_ssize;
+        unsigned long                   start_code;
+        unsigned long                   start_stack;
+        long                            signal;
+        int                             reserved;
+        struct user_regs_struct         *u_ar0;
+        struct user_fpregs_struct       *u_fpstate;
+        unsigned long                   magic;
+        char                            u_comm[32];
+        int                             u_debugreg[8];
+};
+
+#define PAGE_MASK               (~(PAGE_SIZE-1))
+#define NBPG                    PAGE_SIZE
+#define UPAGES                  1
+#define HOST_TEXT_START_ADDR    (u.start_code)
+#define HOST_STACK_END_ADDR     (u.start_stack + u.u_ssize * NBPG)