compile.c: add a RUBY_EVENT_COVERAGE_LINE event for line coverage

2.5's line coverage measurement was about two times slower than 2.4
because of two reasons; (1) vm_trace uses rb_iseq_event_flags (which
takes O(n) currently where n is the length of iseq) to get an event
type, and (2) RUBY_EVENT_LINE uses setjmp to call an event hook.

This change adds a special event for line coverage,
RUBY_EVENT_COVERAGE_LINE, and adds `tracecoverage` instructions where
the event occurs in iseq.
`tracecoverage` instruction calls an event hook without vm_trace.
And, RUBY_EVENT_COVERAGE_LINE is an internal event which does not
use setjmp.

This change also cancells lineno change due to the deletion of trace
instructions [Feature #14104].  So fixes [Bug #14191].

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61350 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 3 insertions, 3 deletions

diff --git a/insns.def b/insns.def
index 1c20573254..120040c034 100644
--- a/insns.def
+++ b/insns.def
@@ -778,11 +778,11 @@ checkkeyword
 
 /**
   @c setting
-  @e trace a branch
-  @j 分岐を trace する
+  @e fire a coverage event (currently, this is used for line coverage and branch coverage)
+  @j カバレッジイベントを trace する
  */
 DEFINE_INSN
-tracebranch
+tracecoverage
 (rb_num_t nf, VALUE data)
 ()
 ()