[test] Run llvm/test/**/*.yaml & don't run llvm/test/**/*.cxx (not exist)

This patch extends D58439 (`llvm/test/{yaml2obj,obj2yaml}/**/*.yaml`) and runs all
`llvm/test/**/*.yaml`

Many directories have configured `.yaml` (see the deleted lit.local.cfg
files). Yet still some don't configure .yaml and have caused stale tests:

* 8c5825befb7bbb2e76f7eccedc6d3bf26e9b2a6a test/llvm-readobj
* bdc3134e237737dd46b51cd1ecd41ecbbe9f921a test/ExecutionEngine

Just hoist .yaml to `llvm/test/lit.cfg.py`. Also delete .cxx which is
not used.  The number of tests running on my machine increases from 38304 to 38309.
The list of new tests:

```
ExecutionEngine/RuntimeDyld/X86/ELF_x86-64_none.yaml
Object/archive-error-tmp.txt
tools/llvm-ar/coff-weak.yaml
tools/llvm-readobj/ELF/verneed-flags.yaml
tools/obj2yaml/COFF/bss.s
```

Reviewed By: grimar, jhenderson, rupprecht

Differential Revision: https://reviews.llvm.org/D83350

test/Object/lit.local.cfg

@@ -1 +0,0 @@
-config.suffixes = ['.test', '.ll', '.s', '.yaml']

test/ObjectYAML/lit.local.cfg

@@ -1 +0,0 @@
-config.suffixes = ['.yaml']

test/lit.cfg.py

@@ -22,7 +22,7 @@ config.test_format = lit.formats.ShTest(not llvm_config.use_lit_shell)
 
 # suffixes: A list of file extensions to treat as test files. This is overriden
 # by individual lit.local.cfg files in the test subdirectories.
-config.suffixes = ['.ll', '.c', '.cxx', '.test', '.txt', '.s', '.mir']
+config.suffixes = ['.ll', '.c', '.test', '.txt', '.s', '.mir', '.yaml']
 
 # excludes: A list of directories to exclude from the testsuite. The 'Inputs'
 # subdirectories contain auxiliary inputs for various tests in their parent

test/tools/llvm-as/lit.local.cfg

@@ -1,4 +1,2 @@
 if not 'X86' in config.root.targets:
     config.unsupported = True
-
-config.suffixes = ['.ll', '.s', '.test', '.yaml']

test/tools/llvm-dwarfdump/lit.local.cfg

@@ -1 +0,0 @@
-config.suffixes = ['.test', '.ll', '.s', '.yaml']

test/tools/llvm-gsymutil/ARM_AArch64/lit.local.cfg

@@ -1,4 +1,2 @@
 if not ('ARM' in config.root.targets and 'AArch64' in config.root.targets):
     config.unsupported = True
-
-config.suffixes = ['.test', '.yaml']

test/tools/llvm-gsymutil/X86/lit.local.cfg

@@ -1,4 +1,2 @@
 if not 'X86' in config.root.targets:
     config.unsupported = True
-
-config.suffixes = ['.test', '.yaml']

test/tools/llvm-nm/lit.local.cfg

@@ -1,4 +1,2 @@
 if not 'X86' in config.root.targets:
     config.unsupported = True
-
-config.suffixes = ['.ll', '.s', '.test', '.yaml']

test/tools/llvm-objdump/lit.local.cfg

@@ -1 +0,0 @@
-config.suffixes = ['.test', '.ll', '.s', '.yaml', '.txt']

test/tools/llvm-readobj/COFF/lit.local.cfg

@@ -1 +0,0 @@
-config.suffixes.add('.yaml')

test/tools/llvm-xray/X86/lit.local.cfg

@@ -1 +0,0 @@
-config.suffixes = ['.yaml', '.ll', '.txt']

test/tools/obj2yaml/lit.local.cfg

@@ -1 +0,0 @@
-config.suffixes = ['.test', '.yaml']

test/tools/yaml2obj/lit.local.cfg

@@ -1 +0,0 @@
-config.suffixes = ['.test', '.yaml']