Pragma to use or avoid POSIX locales for built-in operations
Description
This pragma tells the compiler to enable (or disable) the use of POSIX locales
for built-in operations (for example, LC_CTYPE for regular expressions,
LC_COLLATE for string comparison, and LC_NUMERIC for number formatting). Each
"use locale" or "no locale" affects statements to the end of the enclosing
block.
