In, https://reviews.llvm.org/D120305, CLANG_DEFAULT_PIE_ON_LINUX was set
to `On` by default. However, neither `-fpie` nor `-fpic` are currently
supported in LLVM Flang. Hence, in this patch the behaviour controlled
with CLANG_DEFAULT_PIE_ON_LINUX is refined not to apply to Flang.
Another way to look at this is that CLANG_DEFAULT_PIE_ON_LINUX is
currently affecting both Clang and Flang. IIUC, the intention for this
CMake variable has always been to only affect Clang. This patch makes
sure that that's the case.
Without this change, you might see errors like this on X86_64:
```
/usr/bin/ld: main.o: relocation R_X86_64_32 against `.bss' can not be used when making a PIE object; recompile with -fPIC
```
I've not experienced any issues on AArch64. That's probably because on
AArch64 some object files happen to be position independent without
needing -fpie or -fpic.
Differential Revision: https://reviews.llvm.org/D128333
This is a follow-up of https://reviews.llvm.org/D125832
(see also https://reviews.llvm.org/D125788 for more context). It simply
removes any remaining references to the `flang` bash script. Note that
that `flang-to-external-fc` remains intact.
This felt worthwhile mentioning in the release notes, which have not
been updated since LLVM 12 (we are approaching LLVM 15 now). I took the
liberty of removing all of the out-dated content and added a note about
the renaming.
Differential Revision: https://reviews.llvm.org/D127094
