cc.v: build with "implicit-function-declaration" and fix declarations

required for the webassembly backend

2

compiler/cc.v

@@ -39,6 +39,9 @@ fn (v mut V) cc() {
 	else {
 		a << '-g'
 	}
+	if v.os != .msvc {
+		a << '-Werror=implicit-function-declaration'
+	}
 
 	for f in v.generate_hotcode_reloading_compiler_flags() {
 		a << f

compiler/cheaders.v

@@ -11,6 +11,11 @@ CommonCHeaders = '
 #include <inttypes.h>  // int64_t etc
 #include <string.h> // memcpy
 
+#ifndef _WIN32
+#include <ctype.h>
+#include <locale.h> // tolower
+#endif
+
 #define EMPTY_STRUCT_DECLARATION
 #define OPTION_CAST(x) (x)
 

vlib/os/os.v

@@ -8,7 +8,10 @@ module os
 #include <signal.h>
 #include <errno.h>
 
-//#include <execinfo.h> // for backtrace_symbols_fd
+$if mac {
+	#include <execinfo.h> // for backtrace and backtrace_symbols_fd
+	#include <libproc.h> // proc_pidpath
+}
 
 /*
 struct dirent {

vlib/time/time.v

@@ -12,6 +12,12 @@ const (
 )
 
 #include <time.h>
+
+$if !windows {
+#include <sys/time.h>
+#include <sys/wait.h>
+}
+
 struct Time {
 pub:
 	year   int