Add jv_mem_strdup*() and callocs too

jv_alloc.c

@@ -1,5 +1,6 @@
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 #include "jv_alloc.h"
 
 struct nomem_handler {
@@ -129,6 +130,30 @@ void* jv_mem_alloc_unguarded(size_t sz) {
   return malloc(sz);
 }
 
+void* jv_mem_calloc(size_t nemb, size_t sz) {
+  void* p = calloc(nemb, sz);
+  if (!p) {
+    memory_exhausted();
+  }
+  return p;
+}
+
+void* jv_mem_calloc_unguarded(size_t nemb, size_t sz) {
+  return calloc(nemb, sz);
+}
+
+char* jv_mem_strdup(const char *s) {
+  char *p = strdup(s);
+  if (!p) {
+    memory_exhausted();
+  }
+  return p;
+}
+
+char* jv_mem_strdup_unguarded(const char *s) {
+  return strdup(s);
+}
+
 void jv_mem_free(void* p) {
   free(p);
 }

jv_alloc.h

@@ -17,6 +17,10 @@ static void jv_mem_invalidate(void* mem, size_t n) {
 
 void* jv_mem_alloc(size_t);
 void* jv_mem_alloc_unguarded(size_t);
+void* jv_mem_calloc(size_t, size_t);
+void* jv_mem_calloc_unguarded(size_t, size_t);
+char* jv_mem_strdup(const char *);
+char* jv_mem_strdup_unguarded(const char *);
 void jv_mem_free(void*);
 __attribute__((warn_unused_result)) void* jv_mem_realloc(void*, size_t);