Add missing ansi_fp.h

libc/ansi_fp.h

@@ -0,0 +1,26 @@
+#ifndef _ANSI_FP
+#define _ANSI_FP
+
+#define SIGDIGLEN 36
+typedef struct decimal {
+  char sgn;
+  char unused;
+  short exp;
+  struct {
+    unsigned char length;
+    unsigned char text[SIGDIGLEN];
+    unsigned char unused;
+  } sig;
+} decimal;
+
+typedef struct decform {
+  char style;
+  char unused;
+  short digits;
+} decform;
+
+
+void __num2dec(const decform* f, double x, decimal* d);
+double __dec2num(const decimal* d);
+
+#endif // _ANSI_FP