Add a (fake) implementation of powf in liba

Change-Id: I14af6937fecfbe90ab053594e1269fcbc3681b1c

liba/Makefile

@@ -2,5 +2,5 @@ SFLAGS += -Iliba/include
 
 liba/src/external/sqlite/mem5.o: CFLAGS += -w
 
-objs += $(addprefix liba/src/, assert.o errno.o malloc.o memcpy.o memset.o strcmp.o strlen.o external/sqlite/mem5.o)
+objs += $(addprefix liba/src/, assert.o errno.o malloc.o memcpy.o memset.o powf.o strcmp.o strlen.o external/sqlite/mem5.o)
 tests += $(addprefix liba/test/, stdint.c)

liba/include/math.h

@@ -0,0 +1,12 @@
+#ifndef LIBA_ASSERT_H
+#define LIBA_ASSERT_H
+
+#include "private/macros.h"
+
+LIBA_BEGIN_DECLS
+
+float powf(float x, float y);
+
+LIBA_END_DECLS
+
+#endif

liba/src/powf.c

@@ -0,0 +1,3 @@
+float powf(float x, float y) {
+  return 1.0f; // TODO: do this for real
+}