fix: missing headers in C examples

PR-URL: 	#1958
Reviewed-by: Athan Reines <kgryte@gmail.com>
Reviewed-by: Pranav Goswami <goswami.4@iitj.ac.in>

Author: performant23

lib/node_modules/@stdlib/math/base/special/bernoulli/examples/c/example.c

@@ -18,6 +18,7 @@
 
 #include "stdlib/math/base/special/bernoulli.h"
 #include <stdio.h>
+#include <stdint.h>
 
 int main( void ) {
 	int32_t i;

lib/node_modules/@stdlib/math/base/special/fast/pow-int/README.md

@@ -207,6 +207,7 @@ double stdlib_base_fast_pow( const double x, const int32_t y );
 #include "stdlib/math/base/special/fast/pow.h"
 #include <stdlib.h>
 #include <stdio.h>
+#include <stdint.h>
 
 int main( void ) {
     const double x[] = { 3.14, 2.0, 2.0, 0.0 };

lib/node_modules/@stdlib/math/base/special/fast/pow-int/examples/c/example.c

@@ -18,6 +18,7 @@
 
 #include "stdlib/math/base/special/fast/pow.h"
 #include <stdio.h>
+#include <stdint.h>
 
 int main( void ) {
 	const double x[] = { 3.14, 2.0, 2.0, 0.0 };