P4136R2 #line is not in line with existing implementation

Fixes NB FR-009-108 (C++ CD).

Author: jensmaurer

source/preprocessor.tex

@@ -2097,9 +2097,8 @@
 the following sequence of source lines begins with a
 source line that has a line number as specified
 by the digit sequence (interpreted as a decimal integer).
-If the digit sequence specifies zero
-or a number greater than 2147483647,
-the program is ill-formed.
+Digit sequences representing a number
+outside of the range \crange{1}{2147483647} are conditionally supported.
 
 \pnum
 A preprocessing directive of the form