Time doc: documentation that the CLOCK_* constants and clock_*() functions are

not always available.

Doc/library/time.rst

@@ -141,6 +141,8 @@ The module defines the following functions and data items:
 
    Return the resolution (precision) of the specified clock *clk_id*.
 
+   Availability: Unix.
+
    .. versionadded:: 3.3
 
 
@@ -148,6 +150,8 @@ The module defines the following functions and data items:
 
    Return the time of the specified clock *clk_id*.
 
+   Availability: Unix.
+
    .. versionadded:: 3.3
 
 
@@ -155,6 +159,8 @@ The module defines the following functions and data items:
 
    Set the time of the specified clock *clk_id*.
 
+   Availability: Unix.
+
    .. versionadded:: 3.3
 
 
@@ -164,6 +170,8 @@ The module defines the following functions and data items:
    hardware source, and may give close to nanosecond resolution. CLOCK_HIGHRES
    is the nonadjustable, high-resolution clock.
 
+   Availability: Solaris.
+
    .. versionadded:: 3.3
 
 
@@ -172,6 +180,8 @@ The module defines the following functions and data items:
    Clock that cannot be set and represents monotonic time since some
    unspecified starting point.
 
+   Availability: Unix.
+
    .. versionadded:: 3.3
 
 
@@ -189,6 +199,8 @@ The module defines the following functions and data items:
 
    High-resolution per-process timer from the CPU.
 
+   Availability: Unix.
+
    .. versionadded:: 3.3
 
 
@@ -197,6 +209,8 @@ The module defines the following functions and data items:
    System-wide real-time clock. Setting this clock requires appropriate
    privileges.
 
+   Availability: Unix.
+
    .. versionadded:: 3.3
 
 
@@ -204,6 +218,8 @@ The module defines the following functions and data items:
 
    Thread-specific CPU-time clock.
 
+   Availability: Unix.
+
    .. versionadded:: 3.3