Remove additional historical information

Author: rcvalle

src/doc/rustc/src/exploit-mitigations.md

@@ -160,10 +160,7 @@ and unsigned integer computations that cannot be represented in their type,
 resulting in an overflow or wraparound.
 
 The Rust compiler supports integer overflow checks, and enables it when
-debug assertions are enabled since version 1.0.0 (2015-05-15)[14]–[17], but
-support for it was not completed until version 1.1.0 (2015-06-25)[16]. An
-option to control integer overflow checks was later stabilized in version
-1.17.0 (2017-04-27)[18]–[20].
+debug assertions are enabled since version 1.1.0 (2015-06-25)[14]–[20].
 
 ```rust
 fn main() {