Support PIO Wl-T and Arduino -T linking properly (#6095)

The interrupt vectors in IRAM are omitted 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 PIO build script.

Should have no impact on the Arduino side.

Fixes #6087

tools/platformio-build.py

@@ -89,7 +89,12 @@ env.Append(
         "-Wl,-wrap,spi_flash_read",
         "-u", "app_entry",
         "-u", "_printf_float",
-        "-u", "_scanf_float"
+        "-u", "_scanf_float",
+        "-u", "_DebugExceptionVector",
+        "-u", "_DoubleExceptionVector",
+        "-u", "_KernelExceptionVector",
+        "-u", "_NMIExceptionVector",
+        "-u", "_UserExceptionVector"
     ],
 
     CPPDEFINES=[