[sanitizer] Delete extra whitespace.
C++ modules: fix a bug where loading a declaration with some name would prevent
name lookup from lazily deserializing the other declarations with the same
name, by tracking a bit to indicate whether a name in a DeclContext might have
additional external results. This also allows lazier reconciling of the lookup
table if a module import adds decls to a pre-existing DC.

However, this exposes a pre-existing bug, which causes a regression in
test/Modules/decldef.mm: if we have a reference to a declaration, and a
later-imported module adds a redeclaration, nothing causes us to load that
redeclaration when we use or emit the reference (which can manifest as a
reference to an undefined inline function, a use of an incomplete type, and so
on). decldef.mm has been extended with an additional testcase which fails with
or without this change.
Additional fix for PR16752 and for commit 190044:
-- For TargetInfo::getRealTypeByWidth also added support for IEEEQuad float type.
[sanitizer] Fix PR17138.

strerror_r on OSX returns a positive error code when the errno value is
unknown. Buffer contents are initialized in any case.
The OpenCL standard specifies the sizes and alignments of various types than other C-family
languages, as well as specifying errno is not set by the math functions. Make the
clang front-end set those appropriately when the OpenCL language option is set.

Patch by Erik Schnetter!
Commit 190296 missed out the tests; add them now. Note that it actually tests
"long long" which is currently technically only "reserved for future" use in OpenCL, but
since clang in OpenCL mode supports it we may as well test the modifications to
the settings made for that type.
XCore target: fix weak linkage attribute handling
XCore target: change to Sched::Source

This sidesteps a bug in PrescheduleNodesWithMultipleUses() which
does not check if callResources will be affected by the transformation.
XCore handling of thread local lowering

Fix XCoreLowerThreadLocal trying to initialise globals
which have no initializer.

Add handling of const expressions containing thread local variables.
These need to be replaced with instructions, as the thread ID is
used to access the thread local variable.