dwarf: sync getIdFromTrivialExpr with exprIsTrivial (test break028 and others)

Summary:
The bug manifests when built with
    EXTRA_HC_OPTS += -g

+++ ./ghci.debugger/scripts/break028.run.stderr 2014-12-19 23:08:46.199876621 +0000
@@ -0,0 +1,11 @@
+ghc-stage2: panic! (the 'impossible' happened)
+  (GHC version 7.9.20141219 for x86_64-unknown-linux):
+       getIdFromTrivialExpr x_alJ
+
+Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
+
+
+<interactive>:3:1: Not in scope: ‘g’
+
+<interactive>:3:3: Not in scope: data constructor ‘False’

Signed-off-by: Sergei Trofimovich <siarheit@google.com>

Reviewers: simonmar, austin, scpmw

Reviewed By: scpmw

Subscribers: carter, thomie

Differential Revision: https://phabricator.haskell.org/D580

(cherry picked from commit 30fdf86eec34711be07c6771b02a6fc81ac99ee2)
Rename NamedWildcards flag to NamedWildCards

Summary:
Mind the capital C. As there is already a flag RecordWildCards with a capital
C, we should at least try to be consistent in the spelling of WildCards.

Test Plan: validate

Reviewers: goldfire, simonpj, austin

Reviewed By: simonpj, austin

Subscribers: carter, thomie

Differential Revision: https://phabricator.haskell.org/D584

(cherry picked from commit 089222c9d6798c79179264e5c77c31d5c460a880)
Fix panic on :kind _ in GHCi (Trac #9879)

Summary:
Running `:kind _` in GHCi produced a panic, fix it by extracting the
wildcards. Now, `:kind _` produces `_ :: k0`. Unfortunately, a `0` is
added after the kind is tidied and I haven't found a way to get rid of
it...

This does not fix the other panic involving TemplateHaskell mentioned
in #9879.

Test Plan: new test GHCiWildcardKind should pass

Reviewers: austin, simonpj

Reviewed By: austin

Subscribers: simonpj, carter, thomie, monoidal

Differential Revision: https://phabricator.haskell.org/D572

GHC Trac Issues: #9879

(cherry picked from commit 6eb86a56135a9274d2c958a2ccf4df510c9dab86)
Groom comments related to StaticPointers.

Reviewed By: austin

Differential Revision: https://phabricator.haskell.org/D575

(cherry picked from commit c72f61c6d4dd779d61bd0ebc0b1211a84c5b9038)