RFR: 8279301: c1 getObjectSize intrinsic should guard round mask constant

[Sergey Nazarkin]

This is the fix for the issue that was found during the test of arm32 (see JDK-8279300).  Constant verification was added to the arm32 specific code but root cause was not fixed: the constant for logical AND op  can't be encoded directly and should be loaded to a register. **load_immediate** function is sophisticated enough and able to generate LIR_Const on the platforms where it is possible, and load op for arm32.

-------------

Commit messages:
 - 8279301: c1 getObjectSize intrinsic should guard round mask constant

Changes: https://git.openjdk.java.net/jdk/pull/7076/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7076&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8279301
  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7076.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7076/head:pull/7076

PR: https://git.openjdk.java.net/jdk/pull/7076