A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,
void func();
becomes
void func(void);
This is the second batch of tests being updated (there are a significant
number of other tests left to be updated).
Clang implements an enable_if attribute as an extension. Hook up `-Wpedantic`
to issue an extension usage warning when __enable_if__ is used.
llvm-svn: 261192