[TCWG-1368] Tracked down libfuzzer buildbot failures on aarch64 and raised PR [TCWG-1424] Use profile information for size optimisation - Decided to use clang's 2-stage PGO build as next experiment with compile times on the full test suite as the performance benchmarks - Spent rather too much time trying to inject an extra c-flag into the right stage of the bootstrap builds. As a consolation I know a little bit more about the bootstrap builds. - Just measuring code size the profile guided feedback builds of clang are roughly 33% larger than standard clang, with cold functions optimised for size this drops to 25% larger. Still waiting for performance figures for all runs. It is looking like in its current formulation the size optimisation might offer most of the benefits of PGO but with a lower code size impact. It misses the original goal of keeping the performance of non-PGO optimisation but lower overall size. [Misc] Tracked down a LLD static build failure with a recent glibc. Looks like it won't affect Arm and AArch64 as it is related to X86 relaxed got relocations to ifunc resolvers.

Planned absences - Holiday Monday 9th July