hexadecimal floating point numbers

[ghost]

floating point numbers can be written in hex like
0x7.Ap3
read as (hex)1.2 * 2^3
but it is not recognized as a number in atom such as 0xE5, 10000, 1.5f which are all written in orange

[maxbrunsfeld]

This is fixed via tree-sitter/tree-sitter-c@fd42e75. The fix will go out in Atom 1.38.