DWARF: Fix debug lines in fannkuch -O0 (#2611)

Just some trivial fixes:

* Properly reset prologue after each line (unlike others, this
flag should be reset immediately).

* Test for a function's end address first, as LLVM output appears to
use 1-past-the-end-of-the-function as a location in that function,
and not the next (note the first byte of the next function, which is
ambiguously identical to that value, is used at least in low_pc;
I'm not sure if it's used in debug lines too).

* Ignore the same address if LLVM emitted it more than once, which
it does sometimes.

0 files changed, 0 insertions, 0 deletions