Short circuit default initialization of array elements

[i-garrison]

Implement remaining TODO from bug 543038 where we already checked default init of array element and worst cost will no longer change.

[github-actions]

Test Results

  584 files   -    34    584 suites   - 34   13m 33s ⏱️ - 22m 57s
9 886 tests  - 1 217  9 862 ✅  - 1 097  24 💤  - 120  0 ❌ ±0 
9 924 runs   - 1 194  9 900 ✅  - 1 076  24 💤  - 118  0 ❌ ±0 

Results for commit 3d782a2. ± Comparison against base commit fd06dca.

This pull request removes 1217 tests.

org.eclipse.cdt.debug.gdbjtag.core.tests.jtagdevice.GDBJtagDeviceContributionTest ‑ testGdbJtagDeviceContribution
org.eclipse.cdt.debug.gdbjtag.core.tests.launch.GDBJtagLaunchTest ‑ testGdbJtagLaunch[gdb]
org.eclipse.cdt.debug.gdbjtag.core.tests.launch.GDBJtagLaunchTest ‑ testGdbJtagLaunch[gdbserver]
org.eclipse.cdt.tests.dsf.gdb.tests.CommandLineArgsTest ‑ testSettingArgumentsWithQuotes[gdb]
org.eclipse.cdt.tests.dsf.gdb.tests.CommandLineArgsTest ‑ testSettingArgumentsWithQuotes[gdbserver]
org.eclipse.cdt.tests.dsf.gdb.tests.CommandLineArgsTest ‑ testSettingArgumentsWithSpecialSymbols[gdb]
org.eclipse.cdt.tests.dsf.gdb.tests.CommandLineArgsTest ‑ testSettingArgumentsWithSpecialSymbols[gdbserver]
org.eclipse.cdt.tests.dsf.gdb.tests.CommandLineArgsTest ‑ testSettingArgumentsWithSymbols[gdb]
org.eclipse.cdt.tests.dsf.gdb.tests.CommandLineArgsTest ‑ testSettingArgumentsWithSymbols[gdbserver]
org.eclipse.cdt.tests.dsf.gdb.tests.CommandLineArgsTest ‑ testSettingArgumentsWithTabs[gdb]
…

[jonahgraham]

@i-garrison Thank you for your contribution. I am merging this under the special review policy. As I am in the middle of handling many of these PRs at once, I have done the build and test of them all in #1356 and I am applying the changes back to this PR so that it is tracked properly.