hg: amber/amber: force constant folding to be active in the build

[vicente.romero at oracle.com]

Changeset: 747d35c1b820
Author:    vromero
Date:      2018-04-06 13:40 -0400
URL:       http://hg.openjdk.java.net/amber/amber/rev/747d35c1b820

force constant folding to be active in the build

! make/BuildNashorn.gmk
! make/CompileJavaModules.gmk
! src/jdk.compiler/share/classes/com/sun/tools/javac/code/Source.java
! src/jdk.compiler/share/classes/com/sun/tools/javac/code/Types.java
! src/jdk.compiler/share/classes/com/sun/tools/javac/comp/ConstablesVisitor.java
! src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Gen.java