[Flang][Driver] Add support for PIC
This patch does the following:
- Consumes the PIC flags (fPIC/fPIE/fropi/frwpi etc) in flang-new.
tools::ParsePICArgs() in ToolChains/CommonArgs.cpp is used for this.
- Adds FC1Option to "-mrelocation-model", "-pic-level", and "-pic-is-pie"
command line options.
- Adds the above options to flang/Frontend/CodeGenOptions' data structure.
- Sets the relocation model in the target machine, and
- Sets module flags for the respective PIC/PIE type in LLVM IR.
I have tried my best to replicate how clang does things.
Differential Revision: https://reviews.llvm.org/D131533
Change-Id: I68fe64910be28147dc5617826641cea71b92d94d
14 files changed: