Improve documentation of target hooks for libc functions

	* target.def (libc_has_function, libc_has_fast_function): Improve
	documentation strings.
	* doc/tm.texi: Regenerate.

From-SVN: r274387

gcc/ChangeLog

+2019-08-13  Jonathan Wakely  <jwakely@redhat.com>
+
+	* target.def (libc_has_function, libc_has_fast_function): Improve
+	documentation strings.
+	* doc/tm.texi: Regenerate.
+
 2019-08-13  Caroline Tice  <cmtice@google.com>
 
 	PR other/91396

gcc/doc/tm.texi

@@ -5591,12 +5591,12 @@ macro, a reasonable default is used.
 
 @deftypefn {Target Hook} bool TARGET_LIBC_HAS_FUNCTION (enum function_class @var{fn_class})
 This hook determines whether a function from a class of functions
-@var{fn_class} is present at the runtime.
+@var{fn_class} is present in the target C library.
 @end deftypefn
 
 @deftypefn {Target Hook} bool TARGET_LIBC_HAS_FAST_FUNCTION (int @var{fcode})
 This hook determines whether a function from a class of functions
-@var{fn_class} has a fast implementation.
+@code{(enum function_class)}@var{fcode} has a fast implementation.
 @end deftypefn
 
 @defmac NEXT_OBJC_RUNTIME

gcc/target.def

@@ -2545,14 +2545,14 @@ set via @code{__attribute__}.",
 DEFHOOK
 (libc_has_function,
  "This hook determines whether a function from a class of functions\n\
-@var{fn_class} is present at the runtime.",
+@var{fn_class} is present in the target C library.",
  bool, (enum function_class fn_class),
  default_libc_has_function)
 
 DEFHOOK
 (libc_has_fast_function,
  "This hook determines whether a function from a class of functions\n\
-@var{fn_class} has a fast implementation.",
+@code{(enum function_class)}@var{fcode} has a fast implementation.",
  bool, (int fcode),
  default_libc_has_fast_function)