- Added 2 new builtins strunc_with_overflow and utrunc_with_overflow
that perform truncation and produce a compile time error when truncation
overflows.
- Used these builtins instead of trunc to implement "_convertFromBuiltinIntegerLiteral".
- Currently, the builtins are converted to trunc in IRGen, but we should
not be IRGenning code that uses them, since all uses of
"_convertFromBuiltinIntegerLiteral" should be inlined and the arguments
constant folded.
- I had to change a test and the implementation of operator '~' in the standard library
because they assumed that '0xFF' is a valid signed Int8. It is questionable if we should
allow this and if we should treat signed and unsigned integers differently depending on
how they are spelled (decimal or hexadecimal).
* This patch will be further improved (Ex: will start finding overflows on Int64, better
deal with '-128' after the negative integer literal patch is committed.)
Swift SVN r9226
1d646a8ba8