[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/Transforms/SimplifyCFG/hoist-common-code.ll

@@ -6,12 +6,12 @@ define void @test(i1 %P, i32* %Q) {
         br i1 %P, label %T, label %F
 T:              ; preds = %0
         store i32 1, i32* %Q
-        %A = load i32* %Q               ; <i32> [#uses=1]
+        %A = load i32, i32* %Q               ; <i32> [#uses=1]
         call void @bar( i32 %A )
         ret void
 F:              ; preds = %0
         store i32 1, i32* %Q
-        %B = load i32* %Q               ; <i32> [#uses=1]
+        %B = load i32, i32* %Q               ; <i32> [#uses=1]
         call void @bar( i32 %B )
         ret void
 }