add our previous compat additions to musl src

system/lib/libc/musl/src/compat-emscripten/readme.txt

@@ -0,0 +1,2 @@
+Files in this directory are not strictly standard musl libc, but implemented here for compatibility for Emscripten purposes.
+

system/lib/libc/musl/src/compat-emscripten/strlwr.c

@@ -0,0 +1,12 @@
+#include <ctype.h>
+
+char *strlwr(char *str)
+{
+	char *ret = str;
+	while(*str)
+	{
+		*str = tolower(*str);
+		++str;
+	}
+	return ret;
+}

system/lib/libc/musl/src/compat-emscripten/strtol_l.c

@@ -0,0 +1,22 @@
+#include <stdlib.h>
+#include <ctype.h>
+
+unsigned long long strtoull_l(const char *restrict s, char **restrict p, int base, locale_t loc)
+{
+	return strtoull(s, p, base);
+}
+
+long long strtoll_l(const char *restrict s, char **restrict p, int base, locale_t loc)
+{
+	return strtoll(s, p, base);
+}
+
+unsigned long strtoul_l(const char *restrict s, char **restrict p, int base, locale_t loc)
+{
+	return strtoul(s, p, base);
+}
+
+long strtol_l(const char *restrict s, char **restrict p, int base, locale_t loc)
+{
+	return strtol(s, p, base);
+}

system/lib/libc/musl/src/compat-emscripten/strupr.c

@@ -0,0 +1,12 @@
+#include <ctype.h>
+
+char *strupr(char *str)
+{
+	char *ret = str;
+	while(*str)
+	{
+		*str = toupper(*str);
+		++str;
+	}
+	return ret;
+}