Merge pull request #8353 from opensourcerouting/llvm-20210327

diff --cc .gitignore
Simple merge

diff --cc lib/prefix.h
Simple merge

diff --cc tools/subdir.am
index 6a03a23baa7b33f0ebd47e4823a8b9edba37317f,027763cf91f2f030485a3224526640ffbef636cf..e4b9ecd84ff334c1c5b4dc3069328c0696c899de
--- 1/tools/subdir.am
--- 2/tools/subdir.am
+++ b/tools/subdir.am
@@@ -38,8 -37,8 +38,9 @@@ tools_ssd_CPPFLAGS 
  
  # don't bother autoconf'ing these for a simple optional tool
  llvm_version = $(shell echo __clang_major__ | $(CC) -xc -P -E -)
 +tools_frr_llvm_cg_CPPFLAGS = $(CPPFLAGS_BASE)
  tools_frr_llvm_cg_CFLAGS = $(AM_CFLAGS) `llvm-config-$(llvm_version) --cflags`
+ tools_frr_llvm_cg_CXXFLAGS = $(AM_CXXFLAGS) -O0 -ggdb3 `llvm-config-$(llvm_version) --cxxflags`
  tools_frr_llvm_cg_LDFLAGS = `llvm-config-$(llvm_version) --ldflags --libs`
  tools_frr_llvm_cg_SOURCES = \
        tools/frr-llvm-cg.c \