address review comment

rust-lang#1392 (comment)

Author: tshepang

src/profiling.md

@@ -109,5 +109,5 @@ The llvm-lines output is affected by several options.
 MIR optimizations have little impact. Compared to the default `RUSTFLAGS="-Z
 mir-opt-level=1"`, level 0 adds 0.3GB and level 2 removes 0.2GB.
 As of <!-- date: 2022-07 --> July 2022,
-inlining currently only happens in LLVM,
-but this might change in the future.
+inlining happens in LLVM and GCC codegen backends,
+missing only in the Cranelift one.