Support PIO Wl-T and Arduino -T linking properly

The interrupt vectors in IRAM are ommitted when there is a PROVIDE
statement in the linker control files when using the PIO method of
-Wl,-T<linkfile>.

Drop the PROVIDES (they're in RAM anyway and not ROM related), and
add the required "-u"s to the P{IO build script.

Should have no iumpact on the Arduino side.

Fixes esp8266#6087

tools/platformio-build.py

@@ -93,6 +93,11 @@ def scons_patched_match_splitext(path, suffixes=None):
         "-u", "app_entry",
         "-u", "_printf_float",
         "-u", "_scanf_float"
+        "-u _DebugExceptionVector",
+        "-u _DoubleExceptionVector",
+        "-u _KernelExceptionVector",
+        "-u _NMIExceptionVector",
+        "-u _UserExceptionVector"
     ],
 
     CPPDEFINES=[

tools/sdk/ld/eagle.rom.addr.v6.ld

@@ -41,13 +41,8 @@ PROVIDE ( UartRegReadProc = 0x4000381c );
 PROVIDE ( UartRegWriteProc = 0x400037ac );
 PROVIDE ( UartRxString = 0x40003c30 );
 PROVIDE ( Uart_Init = 0x40003a14 );
-PROVIDE ( _DebugExceptionVector = 0x40000010 );
-PROVIDE ( _DoubleExceptionVector = 0x40000070 );
-PROVIDE ( _KernelExceptionVector = 0x40000030 );
-PROVIDE ( _NMIExceptionVector = 0x40000020 );
 PROVIDE ( _ResetHandler = 0x400000a4 );
 PROVIDE ( _ResetVector = 0x40000080 );
-PROVIDE ( _UserExceptionVector = 0x40000050 );
 PROVIDE ( __adddf3 = 0x4000c538 );
 PROVIDE ( __addsf3 = 0x4000c180 );
 PROVIDE ( __divdf3 = 0x4000cb94 );