[opaque pointer type] Add textual IR support for explicit type parameter to load instruction

Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230794 91177308-0d34-0410-b5e6-96231b3b80d8

test/Feature/packed.ll

@@ -8,8 +8,8 @@
 define void @main() {
         store <4 x float> < float 1.000000e+00, float 2.000000e+00, float 3.000000e+00, float 4.000000e+00 >, <4 x float>* @foo1
         store <2 x i32> < i32 4, i32 4 >, <2 x i32>* @foo2
-        %l1 = load <4 x float>* @foo1           ; <<4 x float>> [#uses=0]
-        %l2 = load <2 x i32>* @foo2             ; <<2 x i32>> [#uses=0]
+        %l1 = load <4 x float>, <4 x float>* @foo1           ; <<4 x float>> [#uses=0]
+        %l2 = load <2 x i32>, <2 x i32>* @foo2             ; <<2 x i32>> [#uses=0]
         ret void
 }