[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/LoopVectorize/scalar-select.ll

@@ -19,9 +19,9 @@ define void @example1(i1 %cond) nounwind uwtable ssp {
 ; <label>:1                                       ; preds = %1, %0
   %indvars.iv = phi i64 [ 0, %0 ], [ %indvars.iv.next, %1 ]
   %2 = getelementptr inbounds [2048 x i32], [2048 x i32]* @b, i64 0, i64 %indvars.iv
-  %3 = load i32* %2, align 4
+  %3 = load i32, i32* %2, align 4
   %4 = getelementptr inbounds [2048 x i32], [2048 x i32]* @c, i64 0, i64 %indvars.iv
-  %5 = load i32* %4, align 4
+  %5 = load i32, i32* %4, align 4
   %6 = add nsw i32 %5, %3
   %7 = getelementptr inbounds [2048 x i32], [2048 x i32]* @a, i64 0, i64 %indvars.iv
   %sel = select i1 %cond, i32 %6, i32 zeroinitializer