runtime: add support for math package

The math package uses routines written in Go assembly language which
LLVM/Clang cannot parse. Additionally, not all instruction sets are
supported.

Redirect all math functions written in assembly to their Go equivalent.
This is not the fastest option, but it gets packages requiring math
functions to work.

testdata/math.go

@@ -0,0 +1,46 @@
+package main
+
+import "math"
+
+func main() {
+	for _, n := range []float64{0.3, 1.5, 2.6, -1.1, -3.1, -3.8} {
+		println("n:", n)
+		println("  asin:     ", math.Asin(n))
+		println("  asinh:    ", math.Asinh(n))
+		println("  acos:     ", math.Acos(n))
+		println("  acosh:    ", math.Acosh(n))
+		println("  atan:     ", math.Atan(n))
+		println("  atanh:    ", math.Atanh(n))
+		println("  atan2:    ", math.Atan2(n, 0.2))
+		println("  cbrt:     ", math.Cbrt(n))
+		println("  ceil:     ", math.Ceil(n))
+		println("  cos:      ", math.Cos(n))
+		println("  cosh:     ", math.Cosh(n))
+		println("  erf:      ", math.Erf(n))
+		println("  erfc:     ", math.Erfc(n))
+		println("  exp:      ", math.Exp(n))
+		println("  expm1:    ", math.Expm1(n))
+		println("  exp2:     ", math.Exp2(n))
+		println("  floor:    ", math.Floor(n))
+		f, e := math.Frexp(n)
+		println("  frexp:    ", f, e)
+		println("  hypot:    ", math.Hypot(n, n*2))
+		println("  ldexp:    ", math.Ldexp(n, 2))
+		println("  log:      ", math.Log(n))
+		println("  log1p:    ", math.Log1p(n))
+		println("  log10:    ", math.Log10(n))
+		println("  log2:     ", math.Log2(n))
+		println("  max:      ", math.Max(n, n+1))
+		println("  min:      ", math.Min(n, n+1))
+		println("  mod:      ", math.Mod(n, n+1))
+		i, f := math.Modf(n)
+		println("  modf:     ", i, f)
+		println("  pow:      ", math.Pow(n, n))
+		println("  remainder:", math.Remainder(n, n+0.2))
+		println("  sin:      ", math.Sin(n))
+		println("  sinh:     ", math.Sinh(n))
+		println("  tan:      ", math.Tan(n))
+		println("  tanh:     ", math.Tanh(n))
+		println("  trunc:    ", math.Trunc(n))
+	}
+}