Unexport die_out_of_memory

Print more specific error diagnostics than a generic "Out of memory"
when an error happens outside xmalloc.c.

* defs.h (die_out_of_memory): Remove prototype.
* strace.c (strace_popen, init): Call perror_msg_and_die instead
of die_out_of_memory.
* unwind.c (unwind_tcb_init): Likewise.
* xmalloc.c (die_out_of_memory): Add static qualifier.

defs.h

@@ -393,7 +393,6 @@ void error_msg_and_help(const char *fmt, ...)
 	ATTRIBUTE_FORMAT((printf, 1, 2)) ATTRIBUTE_NORETURN;
 void perror_msg_and_die(const char *fmt, ...)
 	ATTRIBUTE_FORMAT((printf, 1, 2)) ATTRIBUTE_NORETURN;
-void die_out_of_memory(void) ATTRIBUTE_NORETURN;
 
 void *xmalloc(size_t size) ATTRIBUTE_MALLOC ATTRIBUTE_ALLOC_SIZE((1));
 void *xcalloc(size_t nmemb, size_t size)

strace.c

@@ -566,7 +566,7 @@ strace_popen(const char *command)
 	swap_uid();
 	fp = fdopen(fds[1], "w");
 	if (!fp)
-		die_out_of_memory();
+		perror_msg_and_die("fdopen");
 	return fp;
 }
 
@@ -1750,7 +1750,7 @@ init(int argc, char *argv[])
 #endif
 		case 'E':
 			if (putenv(optarg) < 0)
-				die_out_of_memory();
+				perror_msg_and_die("putenv");
 			break;
 		case 'I':
 			opt_intr = string_to_uint_upto(optarg, NUM_INTR_OPTS - 1);

unwind.c

@@ -113,7 +113,7 @@ unwind_tcb_init(struct tcb *tcp)
 
 	tcp->libunwind_ui = _UPT_create(tcp->pid);
 	if (!tcp->libunwind_ui)
-		die_out_of_memory();
+		perror_msg_and_die("_UPT_create");
 
 	tcp->queue = xmalloc(sizeof(*tcp->queue));
 	tcp->queue->head = NULL;

xmalloc.c

@@ -27,7 +27,7 @@
 
 #include "defs.h"
 
-void die_out_of_memory(void)
+static void die_out_of_memory(void)
 {
 	static bool recursed;