Re-enable netdb tests, fix compiler warning, improve brk coverage

tests/Makefile

@@ -16,10 +16,13 @@ EXPECT_NAMES=\
 	libgen \
 	locale \
 	math \
+	netdb/getaddrinfo \
+	netdb/netdb \
     ptrace \
 	regex \
 	select \
 	setjmp \
+	signal \
 	stdio/all \
 	stdio/buffer \
 	stdio/fgets \
@@ -98,11 +101,7 @@ EXPECT_NAMES=\
 	wchar/wcsstr \
 	wchar/wcstod \
 	wchar/wcstok \
-	wchar/wcstol \
-	signal
-	# TODO: Fix these
-	# netdb/getaddrinfo \
-	# netdb/netdb \
+	wchar/wcstol
 
 # Binaries that may generate varied output
 NAMES=\

tests/expected/netdb/getaddrinfo.stdout

@@ -0,0 +1 @@
+IPv4 address: 23.21.162.66 (www.redox-os.org)

tests/expected/netdb/netdb.stdout

@@ -0,0 +1 @@
+No visible errors occurred!

tests/unistd/brk.c

@@ -5,10 +5,22 @@
 #include "test_helpers.h"
 
 int main(void) {
+	// sbrk report current brk
     void * current = sbrk(0);
     ERROR_IF(sbrk, current, == (void *)-1);
 
-    int status = brk(current + 4096);
+    // sbrk increment and report previous brk
+    void * prev = current;
+    current = sbrk(4096);
+    ERROR_IF(sbrk, current, != prev);
+
+    // sbrk report current break
+    prev = current;
+    current = sbrk(0);
+    ERROR_IF(sbrk, current, != (void*)((uintptr_t)prev + 4096));
+
+    // brk set break to new value
+    int status = brk((void*)((uintptr_t)current + 4096));
     ERROR_IF(brk, status, == -1);
     UNEXP_IF(brk, status, != 0);
 }