This is a class intended to improve errno handling for internal
functions by allowing functions to return their result and error status
instead of setting errno. This specific class will be used for
strtointeger and (in a followup patch) strtofloat.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D133163
rename str_conv_utils to str_to_integer to be more
in line with str_to_float.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D113061
Updates the internal string conversion function so that it
uses the new Limits.h added in a previous commit for max and min values,
and has a templated type. This makes implementing the other strto*
functions very simple.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D107999
