More compat work. Rename libraries from LibFoo.a => libfoo.a

This makes it more straightforward to build a cross-compiler toolchain.
Also move math stuff from LibC to LibM.

LibM/math.h

@@ -0,0 +1,57 @@
+#pragma once
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+#define HUGE_VAL 1e10000
+
+double acos(double);
+float acosf(float);
+double asin(double);
+float asinf(float);
+double atan(double);
+float atanf(float);
+double atan2(double, double);
+float atan2f(float, float);
+double cos(double);
+float cosf(float);
+double cosh(double);
+float coshf(float);
+double sin(double);
+float sinf(float);
+double sinh(double);
+float sinhf(float);
+double tan(double);
+float tanf(float);
+double tanh(double);
+float tanhf(float);
+double ceil(double);
+float ceilf(float);
+double floor(double);
+float floorf(float);
+double round(double);
+float roundf(float);
+double fabs(double);
+float fabsf(float);
+double fmod(double, double);
+float fmodf(float, float);
+double exp(double);
+float expf(float);
+double frexp(double, int* exp);
+float frexpf(float, int* exp);
+double log(double);
+float logf(float);
+double log10(double);
+float log10f(float);
+double sqrt(double);
+float sqrtf(float);
+double modf(double, double*);
+float modff(float, float*);
+double ldexp(double, int exp);
+float ldexpf(float, int exp);
+
+double pow(double x, double y);
+
+__END_DECLS
+