Stop using C headers

CODING_STANDARD.md

@@ -107,6 +107,9 @@ Here a few minimalistic coding rules for the CPROVER source tree.
   include in the source file. For example, given `foo.h` and `foo.cpp`, the
   line `#include "foo.h"` should precede all other include statements in
   `foo.cpp`.
+- Use the C++ versions of C headers (e.g. `cmath` instead of `math.h`).
+  Some of the C headers use macros instead of functions which can have
+  unexpected consequences.
 
 # Makefiles
 - Each source file should appear on a separate line

src/util/ieee_float.cpp

@@ -8,9 +8,7 @@ Author: Daniel Kroening, [email protected]
 
 #include "ieee_float.h"
 
-// <cstdint> is yet to come
-#include <stdint.h>
-
+#include <cstdint>
 #include <ostream>
 #include <cassert>
 #include <cmath>

src/util/pipe_stream.cpp

@@ -23,9 +23,9 @@ Module: A stdin/stdout pipe as STL stream
 #else
 #include <sys/types.h>
 #include <sys/wait.h>
-#include <signal.h>
 #include <unistd.h>
 #include <cstring>
+#include <csignal>
 #endif
 
 #define READ_BUFFER_SIZE 1024