Add VHDL Support & Newer Verilog Linters (#2229)

* Added VHDL file support with ghdl compiler
* Update ghdl.vim
* Create vcom.vim
* Create xvhdl.vim
* Update xvlog.vim
* Added documentation for VHDL & Verilog linters
* Added tests to VHDL & Verilog linters

test/handler/test_ghdl_handler.vader

@@ -0,0 +1,26 @@
+Before:
+  runtime ale_linters/vhdl/ghdl.vim
+
+After:
+  call ale#linter#Reset()
+
+Execute(The ghdl handler should parse lines correctly):
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 41,
+  \     'col' : 5,
+  \     'type': 'E',
+  \     'text': "error: 'begin' is expected instead of 'if'"
+  \   },
+  \   {
+  \     'lnum': 12,
+  \     'col' : 8,
+  \     'type': 'E',
+  \     'text': ' no declaration for "i0"'
+  \   },
+  \ ],
+  \ ale_linters#vhdl#ghdl#Handle(bufnr(''), [
+  \   "dff_en.vhd:41:5:error: 'begin' is expected instead of 'if'",
+  \   '/path/to/file.vhdl:12:8: no declaration for "i0"',
+  \ ])

test/handler/test_vcom_handler.vader

@@ -0,0 +1,36 @@
+Before:
+  runtime ale_linters/vhdl/vcom.vim
+
+After:
+  call ale#linter#Reset()
+
+Execute(The vcom handler should parse lines correctly):
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 218,
+  \     'type': 'W',
+  \     'text': '(vcom-1236) Shared variables must be of a protected type.'
+  \   },
+  \   {
+  \     'lnum': 73,
+  \     'type': 'E',
+  \     'text': '(vcom-1136) Unknown identifier "aresetn".'
+  \   },
+  \   {
+  \     'lnum': 73,
+  \     'type': 'E',
+  \     'text': 'Bad resolution function (STD_LOGIC) for type (error).'
+  \   },
+  \   {
+  \     'lnum': 73,
+  \     'type': 'E',
+  \     'text': 'near ":": (vcom-1576) expecting ";" or ")".'
+  \   },
+  \ ],
+  \ ale_linters#vhdl#vcom#Handle(bufnr(''), [
+  \   '** Warning: ../path/to/file.vhd(218): (vcom-1236) Shared variables must be of a protected type.',
+  \   '** Error: tb_file.vhd(73): (vcom-1136) Unknown identifier "aresetn".',
+  \   '** Error: tb_file.vhd(73): Bad resolution function (STD_LOGIC) for type (error).',
+  \   '** Error: tb_file.vhd(73): near ":": (vcom-1576) expecting ";" or ")".',
+  \ ])

test/handler/test_vlog_handler.vader

@@ -0,0 +1,24 @@
+Before:
+  runtime ale_linters/verilog/vlog.vim
+
+After:
+  call ale#linter#Reset()
+
+Execute(The vlog handler should parse lines correctly):
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 7,
+  \     'type': 'W',
+  \     'text': '(vlog-2623) Undefined variable: C.'
+  \   },
+  \   {
+  \     'lnum': 1,
+  \     'type': 'E',
+  \     'text': '(vlog-13294) Identifier must be declared with a port mode: C.'
+  \   },
+  \ ],
+  \ ale_linters#verilog#vlog#Handle(bufnr(''), [
+  \   '** Warning: add.v(7): (vlog-2623) Undefined variable: C.',
+  \   '** Error: file.v(1): (vlog-13294) Identifier must be declared with a port mode: C.',
+  \ ])

test/handler/test_xvhdl_handler.vader

@@ -0,0 +1,24 @@
+Before:
+  runtime ale_linters/vhdl/xvhdl.vim
+
+After:
+  call ale#linter#Reset()
+
+Execute(The xvhdl handler should parse lines correctly):
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 17,
+  \     'type': 'E',
+  \     'text': '[VRFC 10-91] aresetn is not declared '
+  \   },
+  \   {
+  \     'lnum': 128,
+  \     'type': 'E',
+  \     'text': '[VRFC 10-91] m_axis_tx_tdata is not declared '
+  \   },
+  \ ],
+  \ ale_linters#vhdl#xvhdl#Handle(bufnr(''), [
+  \   'ERROR: [VRFC 10-91] aresetn is not declared [/path/to/file.vhd:17]',
+  \   'ERROR: [VRFC 10-91] m_axis_tx_tdata is not declared [/home/user/tx_data.vhd:128]',
+  \ ])

test/handler/test_xvlog_handler.vader

@@ -0,0 +1,18 @@
+Before:
+  runtime ale_linters/verilog/xvlog.vim
+
+After:
+  call ale#linter#Reset()
+
+Execute(The xvlog handler should parse lines correctly):
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 5,
+  \     'type': 'E',
+  \     'text': '[VRFC 10-1412] syntax error near output '
+  \   },
+  \ ],
+  \ ale_linters#verilog#xvlog#Handle(bufnr(''), [
+  \   'ERROR: [VRFC 10-1412] syntax error near output [/path/to/file.v:5]',
+  \ ])