Allow alias to point to an arbitrary ConstantExpr.

This  patch changes GlobalAlias to point to an arbitrary ConstantExpr and it is
up to MC (or the system assembler) to decide if that expression is valid or not.

This reduces our ability to diagnose invalid uses and how early we can spot
them, but it also lets us do things like

@test5 = alias inttoptr(i32 sub (i32 ptrtoint (i32* @test2 to i32),
                                 i32 ptrtoint (i32* @bar to i32)) to i32*)

An important implication of this patch is that the notion of aliased global
doesn't exist any more. The alias has to encode the information needed to
access it in its metadata (linkage, visibility, type, etc).

Another consequence to notice is that getSection has to return a "const char *".
It could return a NullTerminatedStringRef if there was such a thing, but when
that was proposed the decision was to just uses "const char*" for that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210062 91177308-0d34-0410-b5e6-96231b3b80d8
Process::GetRandomNumber(): fix insecure RNG

This could have generated non-random output under error conditions in release
builds.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210065 91177308-0d34-0410-b5e6-96231b3b80d8
[AArch64] Correctly deal with VPR stack parameter passing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210067 91177308-0d34-0410-b5e6-96231b3b80d8
Ignore line numbers on debug intrinsics. Add an assert to ensure that we aren't emitting line number zero, the .gcno format uses this to indicate that the next field is a filename.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210068 91177308-0d34-0410-b5e6-96231b3b80d8
Make this operator bool() explicit to match the standard library.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210072 91177308-0d34-0410-b5e6-96231b3b80d8
Make this operator bool() explicit to match the standard library.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210073 91177308-0d34-0410-b5e6-96231b3b80d8
Remove the last unspecified_bool_type from llvm.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210076 91177308-0d34-0410-b5e6-96231b3b80d8
Use an enum class.

Might also fix the windows build.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210077 91177308-0d34-0410-b5e6-96231b3b80d8
Use an enum class.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210078 91177308-0d34-0410-b5e6-96231b3b80d8
Add operator== and operator!= to compare with nullptr.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210100 91177308-0d34-0410-b5e6-96231b3b80d8
AArch64: mark small types (i1, i8, i16) as promoted

This means the output of LowerFormalArguments returns a lowered
SDValue with the correct type (expected in SelectionDAGBuilder).
Without this, an assertion under a DEBUG macro triggers when those
types are passed on the stack.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210102 91177308-0d34-0410-b5e6-96231b3b80d8
[asan] Fix coverage instrumentation with -asan-globals=0.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210103 91177308-0d34-0410-b5e6-96231b3b80d8
Implement one operator== with another.

Thanks for David Blaikie for the suggestion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210107 91177308-0d34-0410-b5e6-96231b3b80d8
[AArch64] Add regression tests for the load/store optimizer which cover post-index update folding with sub rather than add.

The tests check that the following transform happens:

  (ldr|str) X, [x20]
   ...
  sub x20, x20, #16
   ->
  (ldr|str) X, [x20], #-16

with X being either w0, x0, s0, d0 or q0.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210113 91177308-0d34-0410-b5e6-96231b3b80d8
[AArch64] Fix typo in load/store optimizer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210114 91177308-0d34-0410-b5e6-96231b3b80d8
Remove some redundant doc comments

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210118 91177308-0d34-0410-b5e6-96231b3b80d8
Update comment. This should have been part of r210062.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210119 91177308-0d34-0410-b5e6-96231b3b80d8
Simplify the parsing of unnamed globals. No functionality changed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210120 91177308-0d34-0410-b5e6-96231b3b80d8
Fix a small bug in the parsing of anonymous globals.

It was able to parse

hidden dllexport global i32 42

but not

dllexport global i32 42

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210121 91177308-0d34-0410-b5e6-96231b3b80d8
Update comments to match reality.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210125 91177308-0d34-0410-b5e6-96231b3b80d8