Core: expose maximum values of time_t and ngx_int_t.

These are needed to detect overflows.

auto/unix

diff --git a/auto/unix b/auto/unix
index 9b4764c..81436b6 100755
--- a/auto/unix
+++ b/auto/unix
@@ -510,6 +510,7 @@
 ngx_type="time_t"; . auto/types/sizeof
 ngx_param=NGX_TIME_T_SIZE; ngx_value=$ngx_size; . auto/types/value
 ngx_param=NGX_TIME_T_LEN; ngx_value=$ngx_max_len; . auto/types/value
+ngx_param=NGX_MAX_TIME_T_VALUE; ngx_value=$ngx_max_value; . auto/types/value
 
 
 # syscalls, libc calls and some features

src/core/ngx_config.h

diff --git a/src/core/ngx_config.h b/src/core/ngx_config.h
index 1da71f8..145e43a 100644
--- a/src/core/ngx_config.h
+++ b/src/core/ngx_config.h
@@ -85,8 +85,11 @@
 
 #if (NGX_PTR_SIZE == 4)
 #define NGX_INT_T_LEN   NGX_INT32_LEN
+#define NGX_MAX_INT_T_VALUE  2147483647
+
 #else
 #define NGX_INT_T_LEN   NGX_INT64_LEN
+#define NGX_MAX_INT_T_VALUE  9223372036854775807
 #endif
 
 

src/os/win32/ngx_win32_config.h

diff --git a/src/os/win32/ngx_win32_config.h b/src/os/win32/ngx_win32_config.h
index 711ad7d..098ca24 100644
--- a/src/os/win32/ngx_win32_config.h
+++ b/src/os/win32/ngx_win32_config.h
@@ -196,6 +196,7 @@
 #define NGX_MAX_SIZE_T_VALUE    9223372036854775807
 #define NGX_TIME_T_LEN          (sizeof("-9223372036854775808") - 1)
 #define NGX_TIME_T_SIZE         8
+#define NGX_MAX_TIME_T_VALUE    9223372036854775807
 
 #else
 
@@ -204,6 +205,7 @@
 #define NGX_MAX_SIZE_T_VALUE    2147483647
 #define NGX_TIME_T_LEN          (sizeof("-2147483648") - 1)
 #define NGX_TIME_T_SIZE         4
+#define NGX_MAX_TIME_T_VALUE    2147483647
 
 #endif