Kernel+LibC: Fix various build issues introduced by ssize_t

Now that ssize_t is derived from size_t, we have to

Libraries/LibC/dirent.cpp

@@ -103,7 +103,7 @@ static int allocate_dirp_buffer(DIR* dirp)
         errno = old_errno;
         return new_errno;
     }
-    size_t size_to_allocate = max(st.st_size, 4096);
+    size_t size_to_allocate = max(st.st_size, static_cast<off_t>(4096));
     dirp->buffer = (char*)malloc(size_to_allocate);
     ssize_t nread = syscall(SC_get_dir_entries, dirp->fd, dirp->buffer, size_to_allocate);
     if (nread < 0) {

Libraries/LibC/stddef.h

@@ -29,7 +29,6 @@
 #ifndef KERNEL
 
 #include <sys/cdefs.h>
-#include <sys/types.h>
 
 #ifdef __cplusplus
 #    define NULL nullptr

Libraries/LibC/stdio.cpp

@@ -993,7 +993,7 @@ void dbgputch(char ch)
     syscall(SC_dbgputch, ch);
 }
 
-int dbgputstr(const char* characters, int length)
+ssize_t dbgputstr(const char* characters, ssize_t length)
 {
     int rc = syscall(SC_dbgputstr, characters, length);
     __RETURN_WITH_ERRNO(rc, rc, -1);

Libraries/LibC/stdio.h

@@ -93,7 +93,7 @@ int fprintf(FILE*, const char* fmt, ...);
 int printf(const char* fmt, ...);
 int dbgprintf(const char* fmt, ...);
 void dbgputch(char);
-int dbgputstr(const char*, ssize_t);
+ssize_t dbgputstr(const char*, ssize_t);
 int sprintf(char* buffer, const char* fmt, ...);
 int snprintf(char* buffer, size_t, const char* fmt, ...);
 int putchar(int ch);

Libraries/LibDebug/Dwarf/Expression.cpp

@@ -41,13 +41,13 @@ Value evaluate(const ByteBuffer& bytes, const PtraceRegisters& regs)
 
         switch (static_cast<Operations>(opcode)) {
         case Operations::RegEbp: {
-            int offset = 0;
+            ssize_t offset = 0;
             stream.read_LEB128_signed(offset);
             return Value { Type::UnsignedIntetger, regs.ebp + offset };
         }
 
         case Operations::FbReg: {
-            int offset = 0;
+            ssize_t offset = 0;
             stream.read_LEB128_signed(offset);
             return Value { Type::UnsignedIntetger, regs.ebp + 2 * sizeof(size_t) + offset };
         }