Add non-release builds

[wesgarland]

Describe your feature request here.

Our build system is hard-coded for Release builds right now.

I added a hook in the cmake so I could override cxx flags via the environment, but this really isn't enough. We should be producing at least two, and ideally four, kinds of builds with our build system

Release

• Symbols Stripped
• Annotations for tools like Breakpad if possible
• Maximum Compiler Optimization (eg -Ofast)
• Assertions disabled

DRelease

• Same as Release
• Except symbols not stripped

Debug

• No optimizations that affect debugging (eg -O0)
• Assertions enabled

Profile

• Same as Debug
• except profiling enabled (eg -pg)

We should also

• have the ability to modify flags for the build steps from the environment
• flags for compiling and linking should be different (eg CXXFLAGS vs LDFLAGS)
• have a C preprocessor symbol which tells us the build type

warning warning warning - older version of SpiderMonkey had different-sized classes based on build type, and I wouldn't be surprised if current versions do. I suggest keeping our build type completely separate from Spidermonkey's.

Code example

No response