Created libc under containers/posix which now all tasks use to build.

There is a problem in the new libc that test0 now misbehaves. Going to be fixed.

containers/posix/libc/src/string.c

@@ -0,0 +1,84 @@
+#include <string.h>
+
+int strlen(const char *s)
+{
+	const char *p;
+
+	for (p = s; *p != '\0'; p++);
+	return p - s;
+}
+
+char *strcpy(char *to, const char *from)
+{
+	char *t = to;
+
+	while ((*to++ = *from++) != '\0')
+		;
+	return t;
+}
+
+void *memset(void *p, int c, int size)
+{
+	char ch;
+	char *pp;
+
+	pp = (char *)p;
+	ch = (char)c;
+
+	for (int i = 0; i < size; i++) {
+		*pp++ = ch;
+	}
+	return p;
+}
+
+void *memcpy(void *d, void *s, int size)
+{
+	char *dst = (char *)d;
+	char *src = (char *)s;
+
+	for (int i = 0; i < size; i++) {
+		*dst = *src;
+		dst++;
+		src++;
+	}
+	return d;
+}
+
+
+int strcmp(const char *s1, const char *s2)
+{
+	unsigned int i = 0;
+	int d;
+
+	while(1) {
+		d = (unsigned char)s1[i] - (unsigned char)s2[i];
+		if (d != 0 || s1[i] == '\0')
+			return d;
+		i++;
+	}
+}
+
+/*
+ * Copies string pointed by @from to string pointed by @to.
+ *
+ * If count is greater than the length of string in @from,
+ * pads rest of the locations with null.
+ */
+char *strncpy(char *to, const char *from, int count)
+{
+	char *temp = to;
+
+	while (count) {
+		*temp = *from;
+
+		/*
+		 * Stop updating from if null
+		 * terminator is reached.
+		 */
+		if (*from)
+			from++;
+		temp++;
+		count--;
+	}
+	return to;
+}